@SergioRamos Bhai as you listed NCERT in your mains strategy, I think preparing some unsolved questions given in them may also help in mains. (if time permits)
Explain the relevance of intergenerational equity in the definition of sustainable development. - This question is given in Indian Economic Development NCERT.
UPSC asked a similar question:
Explain intra-generational and inter-generational issues of equity from the perspective of inclusive growth and sustainable development.