@article{10_4153_CJM_1982_088_4,
     author = {Ohta, Haruto},
     title = {Topological {Extension} {Properties} and {Projective} {Covers}},
     journal = {Canadian journal of mathematics},
     pages = {1255--1275},
     year = {1982},
     volume = {34},
     number = {6},
     doi = {10.4153/CJM-1982-088-4},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CJM-1982-088-4/}
}