Orton, H. D. (1871). Orton's lightning calculator, and accountant's assistant: The shortest, simplest, and most rapid method of computing numbers, adapted to every kind of business, and within the comprehension of every one having the slightest knowledge of figures (Entirely new edition, with extensive modifications and improvements..). Published by W.H. Sadler...
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Orton, Hoy D. Orton's Lightning Calculator, and Accountant's Assistant: The Shortest, Simplest, and Most Rapid Method of Computing Numbers, Adapted to Every Kind of Business, and Within the Comprehension of Every One Having the Slightest Knowledge of Figures. Entirely new edition, with extensive modifications and improvements.. Baltimore: Published by W.H. Sadler.., 1871.
توثيق جمعية اللغة المعاصرة MLA (الطبعة الثامنة)Orton, Hoy D. Orton's Lightning Calculator, and Accountant's Assistant: The Shortest, Simplest, and Most Rapid Method of Computing Numbers, Adapted to Every Kind of Business, and Within the Comprehension of Every One Having the Slightest Knowledge of Figures. Entirely new edition, with extensive modifications and improvements.. Published by W.H. Sadler.., 1871.