https://arxiv.org/abs/1407.0592
[1407.0592] Birational boundedness for holomorphic symplectic varieties, Zarhin's trick for $K3$...
Abstract page for arXiv paper 1407.0592: Birational boundedness for holomorphic symplectic varieties, Zarhin's trick for $K3$ surfaces, and the Tate conjecture
zarhin s trick