↑Vreeland, Nena; Dana, Glenn B.; Hurwitz, Geoffrey B.; Just, Peter; Shinn, R.S. (1977). Area Handbook for Singapore. Washington, D.C.: U.S. Government Printing Office. p. 44. OCLC3032967.
↑"Brief History". Reserve Bank of India. สืบค้นเมื่อ 15 February 2023.