A medieval European ruler (specifically whom and of what country doesn't matter, but may be specified by an answer) one day finds in his bedchamber a group of textbooks and self-improvement books. These books cover a variety topics as understood by modern civilization: logistics/supply chain, industrialization, specialization, leadership, management, and project management. For each topic at least a dozen books directly deal with it, and these books offer multiple angles of discussion, multiple contexts, and multiple opinions on each topic, giving a well-rounded discussion and documentation of each topic. Each book also discusses the stages of advancements of the theory and practice (divorced of such specifics of time and place), so one can understand how each of these topics progressed or regressed over time. Lastly, these books cover how these topics interrelate.
Magically the ruler, his advisors, his noblemen, and his scholars can understand the textbooks (overcoming boundaries of language and cultural context), and thus they can gather understanding of the topics by reading and contemplating the material. The ruler calls all those who can read these books together to study them, and they collectively agree that these were written by a more advanced civilization than their own, and the words should be valued and sought to be understood and then applied.
None of the textbooks discuss modern hard-science, technology, or engineering. The books have also been magically reproduced with period-specific materials, and so the books themselves hold no particular value outside their content (and whatever value being simply a book in that era holds). To rephrase: besides the book-learning, theory, case examples, etc, that they provide there is no noteworthy value to the books.
How valuable actually are these books in terms of potentially resulting economic advancement, and how significantly would the introduction of these books alter history in terms of social and economic advancement?