The research behind the method, with the sources, so you can read them yourself.
Every course carries its own sources, next to the tools that use them.
Job crafting — changing your tasks, your relationships and how you frame the work — is how employees reshape a role from the inside, without changing employer. This is the paper that named it and set out how it works.
Wrzesniewski, A. & Dutton, J. E. (2001). Crafting a job: Revisioning employees as active crafters of their work. Academy of Management Review, 26(2), 179–201. doi.org/10.2307/259118
In 51 work teams in a manufacturing company, teams that felt safe for interpersonal risk-taking did more learning — asking, testing, owning mistakes — and that learning went with better team performance. The study that introduced team psychological safety.
Edmondson, A. (1999). Psychological safety and learning behavior in work teams. Administrative Science Quarterly, 44(2), 350–383. doi.org/10.2307/2666999
Psychological Capital — the HERO resources — is a measurable capacity that can be developed, and it began in organisational research.
Luthans, F., Youssef, C. M. & Avolio, B. J. (2006). Psychological capital: Developing the human competitive edge. Oxford University Press. doi.org/10.1093/acprof:oso/9780195187526.001.0001