@article{10_4153_CMB_1996_038_0,
     author = {Lipparini, Paolo},
     title = {A {Characterization} of {Varieties} with a {Difference} {Term}},
     journal = {Canadian mathematical bulletin},
     pages = {308--315},
     year = {1996},
     volume = {39},
     number = {3},
     doi = {10.4153/CMB-1996-038-0},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CMB-1996-038-0/}
}