@article{AM2_1986__30_137123,
     author = {C. Praagman},
     title = {Iterations and logarithms of formal automorphisms.},
     journal = {Aequationes mathematicae},
     pages = {151--160},
     publisher = {mathdoc},
     volume = {30},
     year = {1986},
     zbl = {0589.39007},
     url = {http://geodesic.mathdoc.fr/item/AM2_1986__30_137123/}
}