Ordered Partitions and Codes Generated by Circulant Matrices. - R. Razen; Jennifer Seberry; Karl H. Wehrhahn (J. Comb. Theory A, 1979)

Chains, multichains and Möbius numbers. - J. W. Breckenridge; K. Varadarajan; Karl H. Wehrhahn (Discret. Math., 1993)

Applications of Narayana's formula. - Karl H. Wehrhahn (Australas. J Comb., 1995)