Those 9 books are:

1. Propaganda: The first book, which deals with the techniques of propaganda and psychological warfare.
2. Physiology: This book discussed physiology and explains how to kill a person simply by touching him or her, known as “The Touch of Death”, simply by the reversal of a nerve impulse. It is also said that the martial art of Judo is a result of a leakage from this book.
3. Microbiology: This book focused on microbiology and biotechnology.
4. Alchemy: This book focused on dealing with alchemy and the transmutation of metals.
5. Communication: The 5th book contained a study of means of communication. Be is terrestrial and extraterrestrial. This alleges that the Nine Unknown were aware of the presence of aliens and the outer world.
6. Gravity: The 6th book contained the secrets of gravity and actual instructions on how to make the Vedic Vimana or simply an aircraft.
7. Cosmogony: This book contained the study of the matters of the universe.
8. Light: The 8th book dealt with light including its speed and how to use it as a weapon.
9. Sociology: The ninth and the last book contains the study of sociology. It included rules for the evolution of societies and the means of foretelling their decline.