Heldman, R. K. (1993). Future telecommunications: Information applications, services & infrastructure. Washington, D.C: McGraw-Hill.
استشهاد بنمط شيكاغوHeldman, Robert K. Future Telecommunications: Information Applications, Services & Infrastructure. Washington, D.C: McGraw-Hill, 1993.
MLA استشهادHeldman, Robert K. Future Telecommunications: Information Applications, Services & Infrastructure. Washington, D.C: McGraw-Hill, 1993.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.