Abanavaz, Fezzeh, and Morteza Khakzar Bafruei. 2020. “Studying a Two-Level Supply Chain Including a Manufacturer and Several Retailers With a Wholesale Price Contract Between Them”. International Review of Management and Marketing 10 (5):165-71. https://econjournals.com.tr/index.php/irmm/article/view/8402.