ebrary, Inc. (1987). Directions in engineering research: An assessment of opportunities and needs. National Academy Press.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)ebrary, Inc. Directions in Engineering Research: An Assessment of Opportunities and Needs. Washington, D.C.: National Academy Press, 1987.
توثيق جمعية اللغة المعاصرة MLA (الإصدار التاسع)ebrary, Inc. Directions in Engineering Research: An Assessment of Opportunities and Needs. National Academy Press, 1987.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.