George, Cœdès (1. januar 1968). The Indianized states of Southeast Asia. East-West Center Press. s. 197. ISBN9780824803681. OCLC961876784. «the Thai military aristocracy distinguished itself at this time from the conquered populations: the ethnic term Thai took on the meaning “free man” in Siamese, this differentiating the Thai from the natives encompassed in Thai society as serfs.».