An improvement of the Gauss' algorithm for solving the diophantine equation $x^2-dy^2=\pm m$ is presented. As an application, multiple continued fraction method is proposed.
Julius M. Basilla. Hideo Wada. "On the solution of $x^2-dy^2=\pm m$." Proc. Japan Acad. Ser. A Math. Sci. 81 (8) 137 - 140, Oct. 2005. https://doi.org/10.3792/pjaa.81.137