Gerards A.M.H. Strong orientations without even directed circuits / A.M.H.Gerards,F.B.Shepherd, 1994. - 15 p. - Текст : непосредственный.
Right angle free subsets in the plane / B.Gamble,W.Pulleyblank,B.Reed,F.B.Shepherd, 1990. - 8 p. - Текст : непосредственный.
Shepherd F.B. Near-perfect matrices / F.B.Shepherd, 1990. - 26 p. - Текст : непосредственный.