The most commonly used index of influenza activity historically has been mortality due to pneumonia and influenza (P&I), which is complicated by factors such as the coding for P&I mortality on death certificates having changed through time, as has the ability of physicians to diagnose these conditions.
Sitzungsberichte der Bayerischen Akademie der Wissenschaften
Miinchen 2019, Heft 2
J 4 - 377
Tome 72, No 12, 2019
Comptes rendus de l'academie bulgare des sciences
J - 2529
March 2020 No. 1 pp.1- 215 Vol. 56
S.T. Yau's solution of the Calabi problem ([ Yau 77, Yau 78]) and later developments had a strong impact on theory of moduli spaces.