@article{giada2015,
author = {Giorgi, Giada},
year = {2015},
month = {02},
pages = {449-457},
title = {An Event-Based Kalman Filter for Clock Synchronization},
volume = {64},
journal = {IEEE Transactions on Instrumentation and Measurement},
doi = {10.1109/TIM.2014.2340631}
}

@misc{rfc5905,
  title={RFC 5905: Network time protocol version 4: Protocol and algorithms specification},
  author={Mills, David and Burbank, J and Kasch, W},
  year={2010},
  publisher={RFC Editor}
}