Gregory, J. Course of civil engineering bcomprising plane trigonometry, surveying, and levelling. With their application to the construction of common roads, railways, canals. Parry 1842.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Gregory, John. Course of Civil Engineering Bcomprising Plane Trigonometry, Surveying, and Levelling. With Their Application to the Construction of Common Roads, Railways, Canals. London: Parry 1842.
توثيق جمعية اللغة المعاصرة MLA (الطبعة الثامنة)Gregory, John. Course of Civil Engineering Bcomprising Plane Trigonometry, Surveying, and Levelling. With Their Application to the Construction of Common Roads, Railways, Canals. Parry 1842.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.