Lawrence, O., & Hutchinson, D. (1990). Computer technology: Digital priniciples to interfacing (2nd ed.). McGraw-hill.

Lawrence, O.R, and D.B Hutchinson. Computer Technology: Digital Priniciples to Interfacing. 2nd ed. Toronto: McGraw-hill, 1990.

Lawrence, O.R, and D.B Hutchinson. Computer Technology: Digital Priniciples to Interfacing. 2nd ed. McGraw-hill, 1990.