Varaporn Saenpholphat. 2008. Gamma labeling of oriented graphs. Bangkok:Srinakharinwirot University;
Varaporn Saenpholphat. (2008) Gamma labeling of oriented graphs (รายงานผลงานวิจัย). Srinakharinwirot University:Bangkok.
Varaporn Saenpholphat. Gamma labeling of oriented graphs. Bangkok:Srinakharinwirot University, 2008.
Varaporn Saenpholphat. (2008) Gamma labeling of oriented graphs (รายงานผลงานวิจัย). Srinakharinwirot University:Bangkok.