@article{10_1017_S001708950000358X,
     author = {Albertson, Michael O. and Berman, David M.},
     title = {An acyclic analogue to {Heawood's} theorem},
     journal = {Glasgow mathematical journal},
     pages = {163--166},
     year = {1978},
     volume = {19},
     number = {2},
     doi = {10.1017/S001708950000358X},
     url = {http://geodesic.mathdoc.fr/articles/10.1017/S001708950000358X/}
}