From Klingon Language Institute Wiki
The official original sources for Klingon words. "canon" refers specifically to pronouncements by Marc Okrand (nobody else can create canon). They are often referred to by abbreviation. (Anyone want to add ones I've missed?)
- The Klingon Dictionary, sometimes in the Addendum.
- The Klingon Way
- Klingon for the Galactic Traveler
- SC (or sometimes SBX)
- Skybox cards
- Conversational Klingon audio tape
- Power Klingon audio tape
- Klingon CD
- Bird of Prey poster, annotated by Okrand
- HolQeD, the journal of the KLI. Not everything in HolQeD is canon, but Dr Okrand sometimes writes articles for it.