@article{10_4153_CJM_1975_083_x,
     author = {Froemke, Jon},
     title = {Maximal {Pre-Primal} {Clusters}},
     journal = {Canadian journal of mathematics},
     pages = {746--751},
     year = {1975},
     volume = {27},
     number = {4},
     doi = {10.4153/CJM-1975-083-x},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CJM-1975-083-x/}
}