Marie-Louise's musings on June 16, commenting on a recent claim that "17% of dementia cases could be prevented by ensuring that your vitamin D levels are sufficient" have stimulated me to comment on this very readable book on Causal Inference that I have recently encountered. There is an online version at https://mixtape.scunning.com/. In the introduction, Scott Cunningham tells the story of how, starting from an ambition to become a poet, he fell in love with empirical research. Elements of Scott the poet show through in a book that makes a great story out of a stance that is rigorous in its insistance on asking the hard questions. It gives a broad overview of methods now available for looking critically at claims made on the basis of observational data. Students who are taking a course on regression will do well to read Chapter 2, and to at least browse the remaining chapters. Stata and R code are provided.
There is what I judge a very fair review at: World Bank Blogs.