@article{INTO_2001_33_a5,
     author = {R. C. Penner},
     title = {The geometry of the {Gauss} product},
     journal = {Itogi nauki i tehniki. Sovremenna\^a matematika i e\"e prilo\v{z}eni\^a. Temati\v{c}eskie obzory},
     pages = {182--212},
     publisher = {mathdoc},
     volume = {33},
     year = {2001},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/INTO_2001_33_a5/}
}