The Hilbert Modular Surface of a Real Quadratic Field. William F. Hammond (1973) Mathematische Annalen
The Tate conjecture for ordinary K3 surfaces over finite fields. N.O. Nygaard (1983) Inventiones mathematicae
Topological and Algebraic Cycles in Kuga-Shimura Varieties. B. Brent Gordon (1987/1988) Mathematische Annalen