For the non-parametric median test for two samples whose sizes $m,n$ satisfy $3\leq m\leq n, m+n \leq 41$, tables of the upper tail probabilities are presented up to the point where 10% is exceeded for the first time.
 J. Hájek Z. Šidák: Theory of rank tests
. Academia, Prague & Academic Press, New York - London 1967. MR 0229351