@article{10_4153_CJM_1973_088_5,
     author = {Heinzer, William and Ohm, Jack},
     title = {An {Essential} {Ring} {Which} is {Not} {A} {v-Multiplication} {Ring}},
     journal = {Canadian journal of mathematics},
     pages = {856--861},
     year = {1973},
     volume = {25},
     number = {4},
     doi = {10.4153/CJM-1973-088-5},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CJM-1973-088-5/}
}