• https://www.weforum.org/agenda/2020/10/top-10-work-skills-of-tomorrow-how-long-it-takes-to-learn-them/
• https://www3.weforum.org/docs/WEF_Towards_a_Reskilling_Revolution.pdf
• https://www2.deloitte.com/us/en/insights/focus/technology-and-the-future-of-work/reskilling-the-workforce.html 
• https://www.bcg.com/en-ca/publications/2018/competing-rate-learning
• https://www.cipd.co.uk/Images/learning-skills-work-report-2021-1_tcm18-95433.pdf