Kirkpatrick, Daniel (2018), Monergism or Synergism: Is Salvation Cooperative or the Work of God Alone?, xiii, "This belief (called monergism) claims salvation is entirely the work of God alone and does not require human cooperation."
Sproul, R.C. (1997), What is Reformed Theology?: Understanding the Basics, p184, "Monergism is the opposite of synergism...Synergism is a cooperative venture, a working together of two or more parties."