Supot Sookyang และ Sayan Panma. (2012) Characterization for non-singularity of some graphs /. Chiang Mai University,:ม.ป.ท.Supot Sookyang และ Sayan Panma. 2012. Characterization for non-singularity of some graphs /. ม.ป.ท.:Chiang Mai University,;Supot Sookyang และ Sayan Panma. Characterization for non-singularity of some graphs /. ม.ป.ท.:Chiang Mai University, 2012. Print.