Ramana MaharshiOnly to such a mind which has gained the inner strength of one-pointedness, Self-enquiry will be successful. But a weak mind will be like wet wood put into the fire of jnana-vichara.

Ramana Maharshi

Kaivalya Upaniṣad Reference Materials:

Video/Audio Lectures

Swami Sarveshananda
5 classes (~90 mins each)

Swami Chinmayananda
8 classes (~60 - 90 mins each)

Class #2 of 8 by Swami Chinmayananda 1975 - Kaivalyopanishad.mov

Swami Viditatmananda
8 classes (search for "Kaivalyopanisad" on the linked page)

Swamini Svatmavidyananda
29 classes (~70 mins each)

Kaivalya Upanishad Verse 2 part 1 by Swamini Svatmavidyananda

Swami Paramarthananda
8 classes (~60 mins each)

Swami Tadatmananda
10 classes (~60 mins each)

Swami Shantananda
5 classes (~60 mins each)