@article{10_4153_CMB_1970_070_6,
     author = {Haff, C. E. and Murty, U. S. R. and Wilton, R. C.},
     title = {A {Note} on {Undirected} {Graphs} {Realizable} as {P.O.} {Sets}},
     journal = {Canadian mathematical bulletin},
     pages = {371--374},
     year = {1970},
     volume = {13},
     number = {3},
     doi = {10.4153/CMB-1970-070-6},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CMB-1970-070-6/}
}