diff --git a/lib/src/app.dart b/lib/src/app.dart
index 8d168d1..3e0d597 100644
--- a/lib/src/app.dart
+++ b/lib/src/app.dart
@@ -1,6 +1,5 @@
 import 'dart:async';
 
-import 'package:firebase_admin/src/firestore/firestore.dart';
 import 'package:firebase_admin/src/storage.dart';
 
 import '../firebase_admin.dart';
diff --git a/lib/src/firestore/firestore.dart b/lib/src/firestore/firestore.dart
index 39cab1b..b616fde 100644
--- a/lib/src/firestore/firestore.dart
+++ b/lib/src/firestore/firestore.dart
@@ -32,18 +32,18 @@ class Firestore implements FirebaseService {
   CollectionReference<Map<String, dynamic>> collection(String id) {
     return CollectionReference(
       firestore: this,
-      path: id,
       fromFirestore: fromFirestore,
       toFirestore: toFirestore,
+      path: id,
     );
   }
 
   DocumentReference<Map<String, dynamic>> doc(String id) {
     return DocumentReference(
       firestore: this,
-      path: id,
       fromFirestore: fromFirestore,
       toFirestore: toFirestore,
+      path: id,
     );
   }
 
@@ -53,8 +53,8 @@ class Firestore implements FirebaseService {
   }) {
     return Transaction.run(
       firestore: this,
-      handler: handler,
       timeout: timeout,
+      handler: handler,
     );
   }
 }
diff --git a/lib/src/firestore/query.dart b/lib/src/firestore/query.dart
index 2f24547..ce6d62a 100644
--- a/lib/src/firestore/query.dart
+++ b/lib/src/firestore/query.dart
@@ -13,8 +13,7 @@ class Query<T> {
   final FromFirestore<T> fromFirestore;
   final String path;
 
-  // FIXME: Remove nullability
-  final StructuredQuery? _query;
+  final StructuredQuery _query;
 
   Query({
     required this.firestore,
@@ -94,7 +93,7 @@ class Query<T> {
       return Filter(
         fieldFilter: FieldFilter(
           field: FieldReference(fieldPath: field),
-          op: 'LESS_THAN',
+          op: op,
           value: serializeValue(value),
         ),
       );
@@ -153,7 +152,7 @@ class Query<T> {
     Cursor? startAt,
     List<Filter>? where,
   }) {
-    final prevWhere = _query?.where;
+    final prevWhere = _query.where;
     final filters = [
       if (prevWhere != null)
         if (prevWhere.compositeFilter?.filters != null)
@@ -168,13 +167,13 @@ class Query<T> {
       fromFirestore: fromFirestore,
       path: path,
       query: StructuredQuery(
-        endAt: endAt ?? _query?.endAt,
-        from: _query?.from, // ???
-        limit: limit ?? _query?.limit,
+        endAt: endAt ?? _query.endAt,
+        from: _query.from, // ???
+        limit: limit ?? _query.limit,
         offset: null, // ???
-        orderBy: orderBy != null ? [...?_query?.orderBy, orderBy] : _query?.orderBy,
+        orderBy: orderBy != null ? [...?_query.orderBy, orderBy] : _query.orderBy,
         select: null, // Returns all document fields.
-        startAt: startAt ?? _query?.startAt,
+        startAt: startAt ?? _query.startAt,
         where: filters.isEmpty
             ? null
             : (filters.singleOrNull ??
@@ -190,11 +189,12 @@ class Query<T> {
 }
 
 class QuerySnapshot<T> {
-  final List<Document> _docs;
   final Firestore firestore;
   final ToFirestore<T> toFirestore;
   final FromFirestore<T> fromFirestore;
 
+  final List<Document> _docs;
+
   @internal
   const QuerySnapshot({
     required this.firestore,
diff --git a/lib/src/firestore/transaction.dart b/lib/src/firestore/transaction.dart
index cdf32a9..52a5812 100644
--- a/lib/src/firestore/transaction.dart
+++ b/lib/src/firestore/transaction.dart
@@ -64,9 +64,9 @@ class Transaction {
   @internal
   static Future<T> run<T>({
     required Firestore firestore,
-    required Future<T> Function(Transaction transaction) handler,
     Duration timeout = const Duration(seconds: 30),
     // int maxAttempts = 5, TODO: Implement it
+    required Future<T> Function(Transaction transaction) handler,
   }) async {
     assert(timeout.inMilliseconds > 0, 'Transaction timeout must be more than 0 milliseconds');
 
diff --git a/lib/src/firestore/utils/document_snapshot.dart b/lib/src/firestore/utils/document_snapshot.dart
index 8fcacfa..bfae562 100644
--- a/lib/src/firestore/utils/document_snapshot.dart
+++ b/lib/src/firestore/utils/document_snapshot.dart
@@ -44,5 +44,5 @@ class _RawDocumentSnapshot extends DocumentSnapshot<Map<String, dynamic>> {
       );
 
   @override
-  Map<String, dynamic> data() => deserializeData(_document.fields!);
+  Map<String, dynamic> data() => deserializeData(firestore, _document.fields!);
 }
diff --git a/lib/src/firestore/utils/serialization.dart b/lib/src/firestore/utils/serialization.dart
index 5d151ce..fa4f225 100644
--- a/lib/src/firestore/utils/serialization.dart
+++ b/lib/src/firestore/utils/serialization.dart
@@ -1,38 +1,46 @@
 import 'package:firebase_admin/src/firestore/document.dart';
 import 'package:googleapis/firestore/v1.dart';
+import 'package:maps_toolkit/maps_toolkit.dart' as maps_toolkit;
+
+import '../firestore.dart';
 
 Map<String, dynamic> fromFirestore(DocumentSnapshot<Map<String, dynamic>> snapshot) =>
     snapshot.data();
 
 Map<String, dynamic> toFirestore(Map<String, dynamic> value) => value;
 
-Map<String, dynamic> deserializeData(Map<String, Value> fields) {
-  return fields.map((key, value) => MapEntry(key, deserializeValue(value)));
+Map<String, dynamic> deserializeData(Firestore firestore, Map<String, Value> fields) {
+  return fields.map((key, value) => MapEntry(key, deserializeValue(firestore, value)));
 }
 
 Map<String, Value> serializeData(Map<String, dynamic> data) {
   return data.map((key, value) => MapEntry(key, serializeValue(value)));
 }
 
-dynamic deserializeValue(Value value) {
+dynamic deserializeValue(Firestore firestore, Value value) {
   if (value.arrayValue != null) {
-    return value.arrayValue!.values!.map(deserializeValue).toList();
+    return value.arrayValue!.values!.map((value) => deserializeValue(firestore, value)).toList();
   } else if (value.booleanValue != null) {
     return value.booleanValue!;
   } else if (value.bytesValue != null) {
-    return null;
+    return null; // TODO: Add support to it
   } else if (value.doubleValue != null) {
     return value.doubleValue!;
   } else if (value.geoPointValue != null) {
-    return null;
+    return maps_toolkit.LatLng(value.geoPointValue!.latitude!, value.geoPointValue!.longitude!);
   } else if (value.integerValue != null) {
     return int.parse(value.integerValue!);
   } else if (value.mapValue != null) {
-    return deserializeData(value.mapValue!.fields!);
+    return deserializeData(firestore, value.mapValue!.fields!);
   } else if (value.nullValue != null) {
     return null;
   } else if (value.referenceValue != null) {
-    return null;
+    return DocumentReference<Map<String, dynamic>>(
+      firestore: firestore,
+      fromFirestore: fromFirestore,
+      toFirestore: toFirestore,
+      path: value.referenceValue!,
+    );
   } else if (value.stringValue != null) {
     return value.stringValue!;
   } else if (value.timestampValue != null) {
@@ -46,11 +54,13 @@ Value serializeValue(dynamic data) {
     booleanValue: data is bool ? data : null,
     bytesValue: null,
     doubleValue: data is double ? data : null,
-    geoPointValue: null,
+    geoPointValue: data is maps_toolkit.LatLng
+        ? LatLng(latitude: data.latitude, longitude: data.longitude)
+        : null,
     integerValue: data is int ? '$data' : null,
     mapValue: data is Map<String, dynamic> ? MapValue(fields: serializeData(data)) : null,
     nullValue: data == null ? 'nullValue' : null,
-    referenceValue: null,
+    referenceValue: data is DocumentReference<Map<String, dynamic>> ? data.path : null,
     stringValue: data is String ? data : null,
     timestampValue: data is DateTime ? '${data.microsecondsSinceEpoch}' : null,
   );
diff --git a/pubspec.yaml b/pubspec.yaml
index d7d47a0..2bdaaf3 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -18,6 +18,7 @@ dependencies:
   http: ^0.13.0
   crypto_keys: ^0.3.0
   collection: ^1.15.0
+  maps_toolkit: ^2.0.1
   gcloud: ^0.8.0
   firebaseapis: ^0.1.2
   snapshot: ^0.2.5