an Entity references as follows:
The Vijñāna-bhairava-tantra (VBT, sometimes spelled in a Hindicised way as Vigyan Bhairav Tantra) is a Shaiva Tantra, of the Kaula Trika tradition of Kashmir Shaivism. Singh notes that it is difficult to establish an exact date for the text, and it could have been written at some time from the 7th to the 8th century CE. It is also called the Śiva-jñāna-upaniṣad by Abhinavagupta.