Gopal, Madan (1990). K.S. Gautam (บ.ก.). India through the ages. Publication Division, Ministry of Information and Broadcasting, Government of India. p. 80.
Monier-Williams, Leumann E, Cappeller C, บ.ก. (2002). "Chakra". A Sanskrit-English Dictionary: Etymologically and Philologically Arranged with Special Reference to Cognate Indo-European Languages, p. 380. Motilal Banarsidass Publications. ISBN9788120831056.