Appendix B: Equivalent Effective Monthly and Annual Finance Rates Converted from Annual Add-On and Discount Rates for Selected Even Monthly Payment Contract Maturities

Wallace P. Mors, Consumer Credit Finance Charges: Rate Information and Quotation (NBER, 1965), https://www.nber.org/books-and-chapters/consumer-credit-finance-charges-rate-information-and-quotation/appendix-b-equivalent-effective-monthly-and-annual-finance-rates-converted-annual-add-and-discount.