What does ØKB stand for (Norwegian source title)?
 

I am doing some research with trees found on some Norwegian websites and keep finding this as a source. It only gives it in a title with a number and side (i.e. ØKB nr. 3, side 93) mainly for birth and christening.

Being Norway and the area (parish) that I'm looking at, I am assuming that it could be Øyer Kirkebøker (Øyer Churchbook) or possibly Øyer Kirkebøker Bergen but I haven't been able to match anything up.

Is my thinking correct or does someone have another idea? Thank you!

Googling for it I have found some references such as:

Title Kirkebok for Øyer-Tretten 1671-1733 Short Title ØKB 1

Kirkebok for Øyer-Tretten 1784-1824 : Short Title: ØKB 3

Kirkebøker for Øyer og Tretten. (ØKB)

Thank you! I appreciate it!