@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},
     year = {1979},
     volume = {17},
     zbl = {0408.06001},
     url = {http://geodesic.mathdoc.fr/item/SF_1979__17_134319/}
}