@article{10_4064_ap76_1_14,
     author = {L. Makar-Limanov},
     title = {AK-invariant, some conjectures,
examples and counterexamples},
     journal = {Annales Polonici Mathematici},
     pages = {139--145},
     publisher = {mathdoc},
     volume = {76},
     number = {1-2},
     year = {2001},
     doi = {10.4064/ap76-1-14},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/ap76-1-14/}
}