Pon Farr is not for you. Stick with what you can understand. -- Vulcan fortune cookie.
"Rule 1: You do not speak of Pon Farr. Rule 2: You DO NOT speak of Pon Farr. Rule 3: Even if one of the participants goes limp or says 'STOP,' Pon Farr is not over . . ."
-- bad round-trip English-Vulcan-English translation of Fight Club.
Seriously, though, it shows up in Spock's World.
And it shows up in The Vulcan Academy Murders,
as I recall.