triennial
preferred label: سه سال یکبار @fa
type: Concept
related: annual

year
preferred label: سال @fa
type: Concept
related: annual

biennial
preferred label: دو سال یکبار @fa
type: Concept
related: annual

periodicity
preferred label: تناوب @fa
type: Concept
narrower: annual

annual
related: year
related: biennial
related: semiannual
related: triennial
alternative label: ANUALMENTE
broader: periodicity
preferred label: سالیانه @fa
type: Concept

semiannual
preferred label: شش‌ماهه @fa
type: Concept
related: annual