@incollection{AST_1991__198-199-200__107_0,
     author = {Dubois, E. and Paysant-Le Roux, R.},
     title = {Sur la longueur du d\'eveloppement en fraction continue de $\sqrt{f} \left( n \right)$},
     booktitle = {Journ\'ees arithm\'etiques de Luminy 17-21 Juillet 1989},
     editor = {Lachaud Gilles},
     series = {Ast\'erisque},
     pages = {107--119},
     publisher = {Soci\'et\'e math\'ematique de France},
     number = {198-199-200},
     year = {1991},
     zbl = {0763.11026},
     mrnumber = {1144316},
     language = {fr},
     url = {http://www.numdam.org/item/AST_1991__198-199-200__107_0/}
}