Appendix D: Aspects of Joint Purchase of a Consumer Durable and of Credit from a Single Seller

F. Thomas Juster and Robert P. Shay, Consumer Sensitivity to Finance Rates: An Empirical and Analytical Investigation (NBER, 1964), https://www.nber.org/books-and-chapters/consumer-sensitivity-finance-rates-empirical-and-analytical-investigation/appendix-d-aspects-joint-purchase-consumer-durable-and-credit-single-seller.