Statistical Tools of Causal Inference are the basic statistical building behind most scientific results. It is thus extremely useful to have an open source collectively aggreed upon resource presenting and assessing them, as well as listing the current unresolved issues. The book Statistical Tools of Causal Inference is an open source resource freely editable by all. You can access the code behind the book on GitHub here. Do not hesitate to make moficiations and push them to the repo.