Sefer Ha'Arachim Vol. 10 (Achdut Hashem)

Compiler: Rabbi Yoel Kahn
Publisher: Kehot Publication Society
Format: 8" x 10½" Hardcover, 250 pages
Language: Hebrew

This  volume 10 in the series of Sefer Ha'Arachim - an Encyclopedia of Chabad Chasidism - covers the theme of the Oneness of Hashem—"Achdut Hashem," a central principle which is foundational to all of Torah, and a major focus of Chabad Chasidism.
The topic of Oneness (which begins in Volumes 8 & 9) is treated comprehensively, also highlighting the Duality within Oneness.
This in-depth and structured analysis is a must for any serious student of Achdut Hashem.