There is a nice article on the subject in a free online magazine on spirituality
akhand-jyoti.org/mayjun04/article4.html
If you like to read more books on various spiritual subjects by the same author (Sri Ram sharma Acharya) please visit where you can download the books for free.
awgp.org/english/books/books_english.html
Also, there is a nice book by Swami shivanada ( A medical doctor by training) titled: THOUGHT POWER
dlshq.org/download/thought_power.htm
Hope you enjoy them…
Vipul patel…