Sách Congruence classes of orientable 2-cell embeddings of bouquets of circles and dipoles

Genus distribution of the equivalence classes of 2-cell embeddings of some graphs such as bouquets of circles and dipoles are known. However, the genus distribution of congruence classes of 2-cell embeddings of graphs is unknown, except a stemmed bouquet, a bouquet with an attaching edge. In fact, Gross, Robbins and Tucker [4] gave a recurrence formula for the genus distribution of congruence classes of a stemmed bouquet.