@article{BallFabian17, author = {Ball, Fabian and Geyer-Schulz, Andreas}, title = {Weak Invariants of Actions of the Automorphism Group of a Graph }, year = {2017}, journal = {Archives of Data Science, Series A}, volume = {2}, number = {1}, pages = {123-144}, doi = {10.5445/KSP/1000058749/02} }