What is non-linear capacitor "varicond"?
How to produce it?

Future energy source will be based on non-linear dielectrics,
which can produce excess energy in charge-discharge cycle due to transformation
of environmental heat in electricity

There is no other book about this special BaTiO3 material

This book is published by Dr. Boris A. Rotenberg in 2000.
245 pages in Russian
500 copies only