The apex of Tantric practices and very, very effective…
…and very challenging. You really need empowerment into this practice and guidance from experienced Tantric.
Books on the subject of Chöd:
Machik’s Complete Explanation: Clarifying the Meaning of Chöd
Chöd: the Sacred Teachings on Severance: Essential Teachings of the Eight Practice Lineages of Tibet
Machig Labdron and the Foundations of Chöd
Chöd Practice Manual and Commentary