1. Carey M: Beads and beadwork of East and South Africa. 1986, Aylesbury: Shire Publications
2. Majupuria TC, Joshi DP: Religious & useful plants of Nepal & India. 1997, India: Gupta Lashkar
3. Li S, Luo X: Compendium of materia medica: bencao gangmu. 2003, Beijing: Foreign Languages Press
4. Wu Z: Flora of Yunnan. 1977, Beijing: Science Press
5. Armstrong WP: Beautiful botanicals: seeds for jewelry. Ornament. 1991, 15: 66-69.