The best productivity tool is interviewing successful people.
I did a search on Bookshare (which I have access to due to having a print-related disability).
So far, there is a lot of common words with "Understanding Information Retrieval Systems" by Marcia Bates
You can download it here: http://libgen.rs/book/index.php?md5=40869A904ABC59F242AA50E8...
But, I don't think that this is what is being copied. But, it could be.
I would not be surprised if mosaic plagiarism is going on, where there is copying going on from a different book for each section. We shall see. I will keep searching.
This is one example of me finding some severe plagiarism where someone makes an entire living off of it: this Language Master "course" (https://www.languagementoring.com/courses/master/order/) which costs 990 EUR is basically this guide, "What do you need to know to learn a foreign language?": https://www.wgtn.ac.nz/lals/resources/paul-nations-resources...
Basically, the entire basis of her course is that above guide, but she creates video lessons for each section of the above linked guide with worksheets for each section (which you fill out to the videos). The only content that she adds that is substantiative in terms of work is language learning resources for X Y and Z languages, in terms of inputs/outputs.
It's weird to see you do these quick Google searches and speculate its plagiarized without any substance to back your argument or awareness of the work he's been doing for years now.
Anyways, there is this guy who is really good at hacking life who describes it and took the course: https://www.youtube.com/watch?v=OP3dA2GcAh8
Anyways, his channel is interesting for sure: https://www.youtube.com/channel/UCoOae5nYA7VqaXzerajD0lg
He was also #1 student in psychology at Cambridge as an undergrad.
Anyways, chances are the course is ideas plagiarized from somewhere else. That's why I have searched for the source. I found a good written source for finding key words to do advanced search queries to find the original source: https://www.rylncoaching.com/post/why-i-have-a-second-brain-...
I found high quality illustrated notes on it, too, which will be really helpful for locating wherever the course material is originally from: https://maggieappleton.com/basb
For searching text of books with advanced queries, the best place is here (world's biggest online library): https://www.bookshare.org/search
Google Books is best for previewing books.