@article{10_4064_cm110_2_10,
     author = {Juan Luis Garc{\'\i}a Guirao and Jaume Llibre},
     title = {Periods of {Morse{\textendash}Smale} diffeomorphisms of $\mathbb S^2$},
     journal = {Colloquium Mathematicum},
     pages = {477--483},
     publisher = {mathdoc},
     volume = {110},
     number = {2},
     year = {2008},
     doi = {10.4064/cm110-2-10},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/cm110-2-10/}
}