Vol. CWSA 29 includes letters on the Aim of Yoga, certain fundamentals of the practice of Integral Yoga such as surrender, equanimity and on the Guru in the Integral Yoga.
CWSA vol. 35 contains letters in which Sri Aurobindo referred
to his life and works, his sadhana or practice of yoga, and the sadhana of members of his ashram.
The last volume contains autobiographical notes, letters and other writings, and includes early personal letters, public statements and letters on national and world events, as well as on his ashram and system of yoga.