Tsongkhapa's commentary entitled A Book of Three Inspirations A Treatise on the Stages of Training in the Profound Path of Naro's Six Dharmas commonly referred to as the Three Inspirations
— by Thupten Jinpa
This is another one book from my Dharma Collection.
It presents Tsongkhapa's instructions on the Six Yogas of Naropa - a preeminent yogic technology system.
Highly recommended.