\begin{thebibliography}{1}

\bibitem{giada2015}
Giada Giorgi.
\newblock An event-based kalman filter for clock synchronization.
\newblock {\em IEEE Transactions on Instrumentation and Measurement},
  64:449--457, 02 2015.

\bibitem{rfc5905}
David Mills, J~Burbank, and W~Kasch.
\newblock Rfc 5905: Network time protocol version 4: Protocol and algorithms
  specification, 2010.

\end{thebibliography}