Missing words and link added

docs/sect-block-production.md

@@ -210,7 +210,7 @@ It is imperative for the security of the network that each block producer correc
 **The calculation described in this section is still to be implemented and deployed**: For now, each block producer is required to synchronize its local clock using NTP instead. The current slot ${s}$ is then calculated by ${s}={t}_{\text{unix}}/{\mathcal{{T}}}$ where ${\mathcal{{T}}}$ is defined in [Definition -def-num-ref-](sect-block-production#defn-epoch-slot) and ${t}_{\text{unix}}$ is defined in [Definition -def-num-ref-](id-cryptography-encoding#defn-unix-time). That also entails that slot numbers are currently not reset at the beginning of each epoch.
 :::
 
-Polkadot does this synchronization without relying on any external clock source (e.g., through the or the ). To stay in synchronization, each producer is therefore required to periodically estimate its local clock offset in relation to the rest of the network.
+Using the median algorithm described in this section, Polkadot achieves synchronization without relying on any external clock source (e.g., through the [NTP](https://en.wikipedia.org/wiki/Network_Time_Protocol) or [GPS](https://en.wikipedia.org/wiki/Global_Positioning_System) protocol). To stay in synchronization, each producer is therefore required to periodically estimate its local clock offset in relation to the rest of the network.
 
 This estimation depends on the two fixed parameters ${k}$ ([Definition -def-num-ref-](sect-block-production#defn-prunned-best)) and ${s}_{{{c}{q}}}$ ([Definition -def-num-ref-](sect-block-production#defn-chain-quality)). These are chosen based on the results of a [formal security analysis](https://research.web3.foundation/Polkadot/protocols/block-production/Babe#5-security-analysis), currently assuming a ${1}{s}$ clock drift per day and targeting a probability lower than ${0.5}\%$ for an adversary to break BABE in 3 years with resistance against a network delay up to $\frac{{1}}{{3}}$ of the slot time and a BABE constant ([Definition -def-num-ref-](sect-block-production#defn-babe-constant)) of ${c}={0.38}$.