New expressions for string loop amplitudes leading to an ultra-simple conception of string dynamics / H.-M.Chan,S.T.Tsou,J.Bordes,L.Nellen, 1990. - 27 p. - Текст : непосредственный.
N-string amplitude as a trace of half-string matrices / Ch.Hong-Mo,J.Bordes,Sh. T.Tsou,L.Nellen, 1989. - 11 p. - Текст : непосредственный.