Schubert varieties in $G/B\times G/B$

Mehta, V. B.; Ramanathan, A.

Compositio Mathematica, Volume 67 (1988) p. 355-358

Equations defining Schubert varieties and Frobenius splittings of diagonals

Ramanathan, A.

Publications Mathématiques de l'IHÉS, Volume 65 (1987) p. 61-90