@article{SF_1979__17_134319, author = {V.M. Sirjaev}, title = {Semilattices of width 3 whose decomposable elements form a chain.}, journal = {Semigroup forum}, pages = {201--240}, publisher = {mathdoc}, volume = {17}, year = {1979}, zbl = {0408.06001}, url = {http://geodesic.mathdoc.fr/item/SF_1979__17_134319/} }