Rungnapa Kongsung และ Wanlapa Aeungmaitrepirom. (2010) Naked-eye detection of lead(II) in aqueous solution by silica gel coated with 1-(2-pyridylazo)-2-naphthol. Chulalongkorn University:ม.ป.ท.Rungnapa Kongsung และ Wanlapa Aeungmaitrepirom. 2010. Naked-eye detection of lead(II) in aqueous solution by silica gel coated with 1-(2-pyridylazo)-2-naphthol. ม.ป.ท.:Chulalongkorn University;Rungnapa Kongsung และ Wanlapa Aeungmaitrepirom. Naked-eye detection of lead(II) in aqueous solution by silica gel coated with 1-(2-pyridylazo)-2-naphthol. ม.ป.ท.:Chulalongkorn University, 2010. Print.