Multivariate Birkhoff-Lagrange interpolation schemes and Cartesian sets of nodes. Crainic, N. — 2004 Acta Mathematica Universitatis Comenianae. New Series
Polya conditions for multivariate Birkhoff interpolation: from general to rectangular sets of nodes. Crainic, M.; Crainic, N. — 2010 Acta Mathematica Universitatis Comenianae. New Series