1. Einiges über Curven und Flächentransformationen;Bäcklund;Lund Universitëts Arsskrift,1874
2. Ricerche sulle superficie a curvatura costante e sulle elicoidi;Bianchi;Annali della R. Scuola normale superiore di Pisa,1879
3. Existence of a Lax pair for any member of the class of nonlinear evolution equations associated to the matrix Schrödinger spectral problem;Bruschi;Lettere al Nuovo Cimento,1980
4. Extension of the Lax method to solve a class of nonlinear evolution equations with x-dependent coeffcients associated to the matrix Schrödinger spectral problem;Bruschi;Lettere al Nuovo Cimento,1980
5. Bäcklund transformations and Lax technique;Bruschi;Lettere al Nuovo Cimento,1980