Cita APA (7th ed.)

Howard, T. L., Hewitt, W. T., Hubbold, R. L., & Wyrmas, K. M. (1991). A practical introduction to PHIGS and PHIGS PLUS. Addison-Wesley.

Cita Chicago (17th ed.)

Howard, T. L., W. T. Hewitt, R. L. Hubbold, i K. M. Wyrmas. A Practical Introduction to PHIGS and PHIGS PLUS. Wokingham: Addison-Wesley, 1991.

Cita MLA (9th ed.)

Howard, T. L., et al. A Practical Introduction to PHIGS and PHIGS PLUS. Addison-Wesley, 1991.