@article{10_4153_CJM_1975_004_2,
     author = {J\'onsson, B. and McNulty, G. and Quackenbush, R.},
     title = {The {Ascending} and {Descending} {Varietal} {Chains} of a {Variety}},
     journal = {Canadian journal of mathematics},
     pages = {25--31},
     year = {1975},
     volume = {27},
     number = {1},
     doi = {10.4153/CJM-1975-004-2},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CJM-1975-004-2/}
}