Shiva Sutras is a manual for the Yoga of Self Realization. It is also a seminal text of Kashmir Shavism in succinct 75 Sutras.
While the Shavite Tantric tradition of self realization is 7,000 to 9,000 years old.
But this text is relatively modern in describing the three secret techniques or Upayas of achieving self realization or ones unification with the Universal Consciousness at will.
These three processes revolve around realizing the following four fundamental keys - Essence of Ultimate Reality, How Reality is Projected, Our Attachment to Material World and Our Liberation by the unveiling of our true nature.