I would also say that it would help if you could be clearer about what you mean by 'implied instruction'.
In case you are interested in school mathematics textbooks, you might find useful papers, and information, in the Proceedings of the International Conference on Mathematics Textbook Research and Development that we held in Southampton in 2014; the full proceedings are online at the link below.
I need to say that I intend to run a study on Iranian high school textbook evaluation with regard to applying implicit instruction specifically pragmatic aspect.
Implicit instruction involves giving students communication-based activities, or having them watch movies or read books, in their target language. ... It involves more of a learning-by-doing approach than explicit instruction.