Browsing Emanuela Grinberga arhīva manuskripti / Manuscripts from the archive of Emanuels Grinbergs by Subject "combinatorics, graph theory, flower snarks"
Facsimile of a manuscript from the archive of Emanuels Grinbergs, University of Latvia.
The article (in three pieces of manuscripts), written in Russian, contains some reflections on graph theory. It may be written in 1973.
The graph on page 30 built from Petersen's graph is the flower snark J5, see http://en.wikipedia.org/wiki/Flower_snark. E. Grinbergs was building these graphs before 1975, when graphs named flower snarks were introduced by Rufus Isaacs.
This fragment of manuscripts, written in Latvian, is taken from a hardcover
notebook of E.Grinbergs. The date when these notes started 29.7.72 is
clearly seen on the first page, on the page 7 the date is 31.8.72, on 10th -
28.8.73.
On page 6, rights, a graph corresponding to flower snark J5 can be clearly
seen, see http://en.wikipedia.org/wiki/Flower_snark. This sample of manuscript
shows that E. Grinbergs was building these graphs before 1975, when
graphs named flower snarks were introduced by Rufus Isaacs.