Lattice paths between diagonal boundaries. Niederhausen, Heinrich — 1998 The Electronic Journal of Combinatorics [electronic only]
A note on the enumeration of diffusion walks in the first octant by their number of contacts with the diagonal. Niederhausen, Heinrich — 2005 Journal of Integer Sequences [electronic only]
Catalan traffic at the beach. Niederhausen, Heinrich — 2002 The Electronic Journal of Combinatorics [electronic only]