摘要

In this note, two classes of quasi-difference matrices, (2n + 2, 4; 1, 1; n)-QDM and (4n + 1, 4; 1, 1; 2n 1)-QDM, are constructed. Combining the known results of quasi-difference matrices and difference matrices, a new short disproof of Euler's conjecture on mutually orthogonal Latin squares is given.