Connection between Sylow subgroups of symmetric group and their semigroups of endomorphismPuusemp, PeeterEesti Teaduste Akadeemia Toimetised. Füüsika. Matemaatika1993 / 2, lk. 144-156

The Moufang'-Mal'tsev symmetries and conservation laws in field theoryLõhmus, Jaak; Paal, Eugen; Sorgsepp, LeoAbst. Int. Con. on Algebra in memory of A.I.Shirshov, Barnaul, August 20-25 1991 : theses on alg. geometry and appl. of algebra in geometry, analysis and theoretical physics1991 / p. 21

О полугруппах эндоморфизмов симметрических группPuusemp, PeeterAlgebraliste süsteemide ehitus ja esitused = Строение и представления алгебраических систем1985 / с. 42-49 https://www.ester.ee/record=b1310238*est http://hdl.handle.net/10062/33914