Generalizing Narayana and Schröder numbers to higher dimensions. Sulanke, Robert A. — 2004 The Electronic Journal of Combinatorics [electronic only]
Bijective recurrences concerning Schröder paths. Sulanke, Robert A. — 1998 The Electronic Journal of Combinatorics [electronic only]
Counting lattice paths by Narayana polynomials. Sulanke, Robert A. — 2000 The Electronic Journal of Combinatorics [electronic only]
Objects counted by the central Delannoy numbers. Sulanke, Robert A. — 2003 Journal of Integer Sequences [electronic only]