Piyawan Canyouk และ Sanong Ekgasit. (2008) Characterization of ballpoint pen inks by ATR FT-IR microspectrocopy. Chulalongkorn University:ม.ป.ท.Piyawan Canyouk และ Sanong Ekgasit. 2008. Characterization of ballpoint pen inks by ATR FT-IR microspectrocopy. ม.ป.ท.:Chulalongkorn University;Piyawan Canyouk และ Sanong Ekgasit. Characterization of ballpoint pen inks by ATR FT-IR microspectrocopy. ม.ป.ท.:Chulalongkorn University, 2008. Print.