@article{DMGT_2007_27_3_a10,
     author = {Ho, Pak},
     title = {A proof of the crossing number of $K_{3,n}$ in a surface},
     journal = {Discussiones Mathematicae. Graph Theory},
     pages = {549--551},
     publisher = {mathdoc},
     volume = {27},
     number = {3},
     year = {2007},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/DMGT_2007_27_3_a10/}
}