@article{10_4153_CMB_1993_009_4,
     author = {Gu{\'\i}\~nez, V. and S\'aez, E. and Sz\'ant\'o, I.},
     title = {Small {Amplitude} {Limit} {Cycles} for {Cubic} {Systems}},
     journal = {Canadian mathematical bulletin},
     pages = {54--63},
     year = {1993},
     volume = {36},
     number = {1},
     doi = {10.4153/CMB-1993-009-4},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CMB-1993-009-4/}
}