Notes on verification

Confirmed by numerous reputable encyclopedic and academic sources; 'c. 980' is the standard consensus figure, though Stanford Encyclopedia of Philosophy notes minor uncertainty in exact year based on autobiographical sources. [cascade flags: aggregator_dropped_primary_exists,wikipedia_dropped_other_sources_exist | tier=silver indep_score=0.9 clusters=5 claim_tier=everyday | framework convergence=partial on Nearly all modern biographical accounts trace ultimately to Avicenna's own autobiography (dictated to his student al-Juzjani), critically edited by Gohlman in 1974, though the specific year is treated as an approximation by convention rather than a precisely attested date. (upstreams: Avicenna's autobiography/biography as preserved and critically edited by W.E. Gohlman (1974), 'The Life of Ibn Sina') — publishers independent, evidence may not be | kind=empirical eligibility=high]