1. Cordial graphs: a weaker version of graceful and harmonious graphs;Cahit;Ars Combin.,1987
2. On friendly index sets of root-unions of stars by cycles;Ho;J. Combin. Math. Combin. Comput.,2007
3. A-cordial graphs;Hovey;Discrete Math.,1991
4. On friendly index sets of generalized books;Kwong;J. Combin. Math. Combin. Comput.,2008
5. On friendly index sets of 2-regular graphs;Kwong;Discrete Math.,2008