J. A. Bondy and U. S. R. Murty (2008). Graph Theory. Graduate Texts in Mathematics, Springer, New York. 244
G. Chartrand, S.-M. Lee and P. Zhang (2006). Uniformly cordial graphs. Discrete Math.. 306, 726-737
H. Kwong, S.-M. Lee and H. K. Ng (2008). On friendly index sets of $2$-regular
graphs. Discrete Math.. 308, 5522-5532
H. Kwong and S.-M. Lee (2008). On friendly index sets of generalized books. J. Combin. Math. Combin. Comput.. 66, 43-58
S.-M. Lee and H. K. Ng (2008). On friendly index sets of bipartite graphs. Ars
Combin.. 86, 257-271
E. Salehi and S.-M. Lee (2006). On friendly index sets of trees. Congr. Numer.. 178, 173-183
W. C. Shiu and H. Kwong (2008). Full friendly index sets of {P}_2times{P}_n. Discrete Math.. 308, 3688-3693
W. C. Shiu and M. H. Ling (2007). Extreme friendly indices of {$C_mtimes C_n$}. Congr. Numer.. 188, 175-182
W. C. Shiu and M. H. Ling (2010). Full friendly index sets of {C}artesian products
of two cycles. Acta Math. Sin. (Engl. Ser.). 26, 1233-1244
W. C. Shiu and F. S. Wong (2009). W. C. Shiu and F. S. Wong. Congr. Numer.. 197, 65-75
W. C. Shiu and F. S. Wong (2012). Full friendly index sets of cylinder graphs. Australas. J. Combin.. 52, 141-162