'Aptavani 13 (Uttarardh)' is the thirteenth in a series of spiritual Audio books titled 'Aptavani'. In this series, Gnani Purush Dada Bhagwan has explained various aspects of attachment-abhorrence, like-dislike, vitaraagata, gnan-agnan, darshan (vision) and other aspects of the knowledge of the Self. This Audio book will help to understand the science of prakruti and the Self (Soul).