@article{SF_1986__33_134790,
     author = {H.J. Shyr},
     title = {Characterizations of right dense languages.},
     journal = {Semigroup forum},
     pages = {23--30},
     publisher = {mathdoc},
     volume = {33},
     year = {1986},
     zbl = {0581.20066},
     url = {http://geodesic.mathdoc.fr/item/SF_1986__33_134790/}
}