Space curves and their duals. Craveiro de Carvalho, F.J.; Robertson, S.A. — 1997 Portugaliae Mathematica
A note on equichordal graphs Craveiro de Carvalho, F.J.; Robertson, S.A. — 1988 Portugaliae mathematica
A correction to "A note on equichordal graphs" (Port. Math., 45(4) (1988), 363-368) Craveiro de Carvalho, F.J.; Robertson, S.A. — 1991 Portugaliae mathematica
Symmetric models of the real projective plane. Farran, H.R.; Pinto, Maria do Rosario; Robertson, S.A. — 1999 Beiträge zur Algebra und Geometrie
Classical solids. Farran, H.R.; d'Azevedo Breda, A.M.; Robertson, S.A. — 1995 Beiträge zur Algebra und Geometrie
Relations Between a Manifold and its Focal Set. S. CARTER; S.A. ROBERTSON — 1967 Inventiones mathematicae