@article{10_1017_S0017089500006881,
     author = {Zomorrodian, Reza},
     title = {Classification of p-groups of automorphisms of {Riemann} surfaces and their lower central series},
     journal = {Glasgow mathematical journal},
     pages = {237--244},
     year = {1987},
     volume = {29},
     number = {2},
     doi = {10.1017/S0017089500006881},
     url = {http://geodesic.mathdoc.fr/articles/10.1017/S0017089500006881/}
}