Ehrig, H.; R. Heckel; M. Korff; M. Löwe; L. Ribeiro; A. Wagner; A. Corradini (1997). "Chapter 4. Algebraic approaches to graph transformation. Part II: single pushout approach and comparison with double pushout approach". In Grzegorz Rozenberg (ed.). Handbook of Graph Grammars and Computing by Graph Transformation. World Scientific. pp. 247–312.
CiteSeerX10.1.1.72.1644.
ISBN978-981-238-472-0.