@article{10_4153_CJM_2008_005_8,
     author = {Gurjar, R. V. and Masuda, K. and Miyanishi, M. and Russell, P.},
     title = {Affine {Lines} on {Affine} {Surfaces} and the {Makar{\textendash}Limanov} {Invariant}},
     journal = {Canadian journal of mathematics},
     pages = {109--139},
     year = {2008},
     volume = {60},
     number = {1},
     doi = {10.4153/CJM-2008-005-8},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CJM-2008-005-8/}
}