@article{10_4153_CJM_2004_033_0,
     author = {Guardo, Elena and Tuyl, Adam Van},
     title = {Fat {Points} in {P1} {\texttimes} {P1} and {Their} {Hilbert} {Functions}},
     journal = {Canadian journal of mathematics},
     pages = {716--741},
     year = {2004},
     volume = {56},
     number = {4},
     doi = {10.4153/CJM-2004-033-0},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CJM-2004-033-0/}
}