Differential Geometry and Its Applications, Proc. Conf. Brno, Czechoslovakia, Aug. 27–Sept. 2, 1989 (World Scientific, Singapore, 1990) 361–371.
A generalization of the $\Cal C$-spectral sequence of A.M. Vinogradov is presented, allowing to overcome certain limitations set by the "Two-line Theorem". Among the terms of the generalized spectral sequence there are the horizontal cohomology groups with general coefficients.