Romanenko Е. А. The semigroup of endotopisms of the equivalence relation / E. Romanenko // International Mathematical Conference : Book of Abstracts of the : On occasion the 70th year anniversary of Professor Vladimir Kirichenko (June 13-19, 2012 ). - Mykolayiv : V.O. Sukhomlynsky National University, 2012. - Р. 170.