2024. EntrepreEntrepreneurship Knowledge, Challenges, and Sustainable Entrepreneurship Framework for Retirees: A Systematic Reviewneurship Knowledge, Challenges, and Sustainable Entrepreneurship Framework for Retirees: A Systematic Review: Introduction, Methodology, Result and Discussion, Discussion, and Conclusion. . International Journal of Innovation and Business Strategy (IJIBS). 19, 2 (Dec. 2024), 1–21. DOI:https://doi.org/10.11113/ijibs.v19.161.