@article{10_4153_CJM_1980_040_x,
     author = {Rankin, S. A. and Reis, C. M.},
     title = {Semigroups with {Quasi-Zeroes}},
     journal = {Canadian journal of mathematics},
     pages = {511--530},
     year = {1980},
     volume = {32},
     number = {3},
     doi = {10.4153/CJM-1980-040-x},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CJM-1980-040-x/}
}