About orthogonal permutations of the group G = G(2)XG(k). (Short Communication). J.-C. Panayiotopoulos — 1978 Aequationes mathematicae
Recherche des collections speciales maximales du groupe G = G ( 2 ) × G ( k ) , k pair J.-C. Panayiotopoulos — 1980 Archivum Mathematicum