Quite distinct from textbooks are research articles. But there are too many of them to read or study. We have found that students are overwhelmed when they search for a single ISP and find on our current library search engines literally hundreds of thousands to millions of articles. It buries and swamps them and reduces their interest in studying.
SO we advise students to first search for REVIEWS that have the ISP specifically in their title. Peer-reviewed REVIEWS often cover an entire field in depth, integrating quite literally hundreds of articles each cited in the text. We insist searching for ISP in title because otherwise the search engines give you any article that has the ISP (often common language uses) anywhere in their text. By focusing on inclusion specifically in the title it ensures that the review is primarily on the topic of interest to them. Or we encourage them to search for their ISP with an application, or another ISP, or a usage. Both of these strategies vastly reduce the number and make the reading and coverage more manageable.
There is a remaining problem with this strategy. Often such peer-reviewed REVIEWS are published in the typical specialty reductionist journal and so restrict coverage to a particular isolated discipline or domain. Using these non-transdisciplinary literatures still requires the abstraction to general systems information typical of the SPT approach. Of course, this is why SPT exists. It is the place to go to find the most massive collection of cross-disciplinary similarities extant.