a yu mkha' 'gro

Exerpted from Boddicitta.net

The wheel of Sharp weapons Effectively Striking the Heart of the foe' has been composed by the great Yogi Dharmaraksita in his retreat in the jungle where many fierce animals pray. What this great Yogi, the possessor of vast scriptural knowledge, the full powers of logic and deep profound insight, has written here is the essence of the teachings of all his holy Gurus. He always practised in accordance with this essence in his fearsome jungle retreat during the degenerate age in which he lived. From among his many disciples, Dharmaraksita transmitted these teachings to Atisa (982--1054); and Atisa practised them wherever he traveled in order to tame those who ware most wild.

The full text can be found at the Berzin Archives or Boddicitta.net