On the minimal canonical realizations of the Lie algebra O c ( n ) M. Havlíček; P. Exner — 1975 Annales de l'I.H.P. Physique théorique
Matrix canonical realizations of the Lie algebra o ( m , n ) . I. Basic formulæ and classification M. Havlíček; P. Exner — 1975 Annales de l'I.H.P. Physique théorique