by Avakian, M.P., Pogosyan, G.S., Sissakian, A.N., Ter-Antonyan, V.M.
Published in Physics letters. A (28.09.1987)

by Sissakian, A.N., Ter-Antonyan, V.M., Pogosyan, G.S., Lutsenko, I.V.
Published in Physics letters. A (15.01.1990)

by Davtyan, L. S., Pogosyan, G. S., Sisakyan, A. N., Ter-Antonyan, V. M.
Published in Theoretical and mathematical physics (01.02.1986)

by Mardoyan, L. G., Pogosyan, G. S., Sisakyan, A. N., Ter-Antonyan, V. M.
Published in Theoretical and mathematical physics (01.06.1985)