Enumeration of labeled connected bicyclic and tricyclic graphs without bridges.

The article discusses on how to obtain the closed-form expressions for the number of labeled bi- and tricyclic graphs and the asymptotics of the number of such graphs. It says that the cyclomatic number of any of those graphs is k +1. It mentions that E. F. Dmitriev used other methods in enumerating abeled 2-edge-connected graphs but has not published his results.