@article{10_4153_CMB_1983_027_6,
     author = {Schirmer, Helga},
     title = {Coincidence {Sets} of {Coincidence} {Producing} {Maps}},
     journal = {Canadian mathematical bulletin},
     pages = {167--170},
     year = {1983},
     volume = {26},
     number = {2},
     doi = {10.4153/CMB-1983-027-6},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CMB-1983-027-6/}
}