MLA

Howard, T.L.J, W.T Hewitt, and R.J Hubbold. A Practical Introduction to Phigs and Phigs Plus. Wokingham: Addison-Wesley, 1991.

APA

Howard, T., Hewitt, W., & Hubbold, R. (1991). A practical introduction to phigs and phigs plus. Wokingham: Addison-Wesley.

Chicago

Howard, T.L.J., W.T Hewitt, and R.J Hubbold. A Practical Introduction to Phigs and Phigs Plus. Wokingham: Addison-Wesley, 1991.