This particular Upanishad comes under the Rig Veda which is a sub-part of the Aitareya Aranyaka. This book consists of commentary by Shankaracharya for better understanding and is an excellent source of information that is relatable to the common man. It explains how the soul is at the centre of everything and how it connects to the divine (paramatma). It teaches you about the creation of the universe as well and how it ties in to everything. It is a book for those who want to explore more and understand the identity of the soul. Get this book from Giri UK.