I will leave you to google the books, but for György Pauk's book, here is what he wrote in the first page:
This book was prepared for publication during the 2020/21 period of the Cpvod-19 pandemic, as everyone knows, this has had a traumatic impact on the classical music community in the UK and overseas, many of those earning their living in this sector of the economy are 'freelance', or self employed and demand for their services has collapsed, as for the student preparing to follow in their footsteps, they are anxiously wondering what the future holds for them
I have decided that all proceeds from the sale of this book will be distributed to charities support young classical musicians.
What a wonderful thing for the author to do. It was (and still is really with all the uncertainty) a terrible time for all creatives and I am so grateful now for their contributions to our quality of life.