Crystal Cave - A Compendium of Teachings by Masters of the Practice Lineage — translated by Erik Pema Kunsang

The fourth book in the Guhyagarbha Series of translations for restricted circulation.

Vajra Heart – by Tulku Urgyen Rinpoche

The second book in the Guhyagarbha series of translations for restricted circulation.

The Kalachakra Tantra - Rite of Initiation For the Stage of Generation – by the XIV Dalai Lama and Jeffrey Hopkins

A commentary on the text of Kay-drup-ge-lek-bel-sang-bo , and the text itself.

Death, Intermediate State, and Rebirth in Tibetan Buddhism — by Jeffrey Hopkins

An excellent companion volume to the Tibetan Books of the Dead , and also contemporary Western works on death and dying.

The Dawn of Tantra — by Chögyam Trungpa and Herbert V. Guenther

Tibetan meditation master and a Western scholar, each of whose grasp of Buddhist tantra is real and unquestionable.

Tantric View of Life
— by Herbert V. Guenther 

The meaning, philosophy and practice of Tantra presented in depth.

Matrix of Mystery - Scientific and Humanistic Aspects of rDzogs-chen Thought — by Herbert V. Guenther

The first comprehensive study of the Dzogchen or Ati tradition of the Nyingma school of Tibetan Buddhism.

Buddhist Philosophy in Theory and Practice — by Herbert V. Guenther

Growth of Buddhist philosophy as an encompassing vision that seeks to discover the Knowable and to reveal the nature of Being.

A Commentary on the Kalachakra Tantra
— by Geshe Ngawang Dhargyey

Contains explanations and advice concerning the various commitments and initial practices.

Vajrayogini - Her Visualizations, Rituals and Forms — by Elizabeth English

Delves into the origins of Vajrayogini, charting her evolution in India and examining her roots in the Chakrasamvara tantra and in Indian tradition.