Discrete Mathematics
Discrete Mathematics > 2009 > 309 > 4 > 655-665
Discrete Mathematics > 2009 > 309 > 6 > 1740-1745
Discrete Mathematics > 2009 > 309 > 6 > 1385-1390
Discrete Mathematics > 2009 > 309 > 13 > 4489-4494
Discrete Mathematics > 2009 > 309 > 18 > 5739-5744