1. On continuation of 3-colouring of planar graphs (in Russian);Aksenov;Diskret. Anal. Novosibirsk,1974
2. A proof of Grünbaum's conjecture on acyclic 5-colourability of planar graphs (in Russian);Borodin;Dokl. Akad. Nauk SSSR,1976
3. On cyclic colorings of planar graphs;Borodin;Discrete Math.,1979
4. Solution of Ringel's problems on vertex-face colouring of plane graphs and colouring of 1-planar graphs (in Russian);Borodin;Diskret. Anal. Novosibirsk,1984
5. Ein Dreifarbensatz für dreikreisfrei Netze auf der Kugel;Grötzsch,1958