Entrepreneurship Knowledge, Challenges, and Sustainable Entrepreneurship Framework for Retirees: A Systematic Review: Introduction, Methodology, Result and Discussion, Discussion, and Conclusion. IJIBS [Internet]. 2024 Dec. 31 [cited 2026 Nov. 14];19(2):56-77. Available from: https://ijibs.utm.my/index.php/ijibs/article/view/161