@article{GDZPPN002064197, title = {An elementary formula for the Fenchel-Nielsen twist.}, journal = {Commentarii mathematici Helvetici}, volume = {56}, year = {1981}, pages = {132-135}, zbl = {0467.30036}, url = {http://dml.mathdoc.fr/item/GDZPPN002064197} }
Wolpert, Scott. An elementary formula for the Fenchel-Nielsen twist.. Commentarii mathematici Helvetici, Tome 56 (1981) pp. 132-135. http://gdmltest.u-ga.fr/item/GDZPPN002064197/