@article{SF_1975__11_134128,
     author = {G. AKST and T.P. Dence},
     title = {Idempotent {Endomorphisms} on {Standard} {Threads.}},
     journal = {Semigroup forum},
     pages = {14--21},
     publisher = {mathdoc},
     volume = {11},
     year = {1975},
     zbl = {0299.20053},
     url = {http://geodesic.mathdoc.fr/item/SF_1975__11_134128/}
}