Multiplicative Designs I: The Normal and Reducible Cases. - William G. Bridges; R. A. Mena (J. Comb. Theory A, 1979)

Multiplicative Designs II. Uniform Normal and Related Structures. - William G. Bridges; R. A. Mena (J. Comb. Theory A, 1979)

Xk-Digraphs. - William G. Bridges; R. A. Mena (J. Comb. Theory B, 1981)

Rational G-Matrices with Rational Eigenvalues. - William G. Bridges; R. A. Mena (J. Comb. Theory A, 1982)

Distance-regular digraphs of girth 4. - Hikoe Enomoto; R. A. Mena (J. Comb. Theory B, 1987)

Certain distance-regular digraphs and related rings of characteristic 4. - Robert A. Liebler; R. A. Mena (J. Comb. Theory A, 1988)