[1] [CITE@en[[[RFC 2783]] - Pulse-Per-Second API for UNIX-like Operating Systems, Version 1.0]], [TIME[2021-04-11T13:49:49.000Z]], [TIME[2021-04-12T08:41:36.180Z]] <https://tools.ietf.org/html/rfc2783>

[2] [CITE[Available implementations of Pulse Per Second (PPS) API]], [TIME[2021-04-12T08:42:30.000Z]] <http://www.ntp.org/ppsapi/PPSImpList.html>