Lewin, C G (1970). "An Early Book on Compound Interest - Richard Witt's Arithmeticall Questions". Journal of the Institute of Actuaries. 96 (1): 121–132. doi:10.1017/S002026810001636X.
Lewin, C G (1981). "Compound Interest in the Seventeenth Century". Journal of the Institute of Actuaries. 108 (3): 423–442. doi:10.1017/S0020268100040865.
Milanfar, Peyman (1996). "A Persian Folk Method of Figuring Interest". Mathematics Magazine. 69 (5): 376. doi:10.1080/0025570X.1996.11996479.
http://laws.justice.gc.ca/en/showdoc/cs/I-15/bo-ga:s_6//en#anchorbo-ga:s_6[permanent dead link] Interest Act (Canada), Department of Justice. The Interest Act specifies that interest is not recoverable unless the mortgage loan contains a statement showing the rate of interest chargeable, "calculated yearly or half-yearly, not in advance." In practice, banks use the half-yearly rate.
