ARMSTEAD, C. H. Geothermal energy its past, present and future contributions to the energy needs of man. E & FN Spon Ltd.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)ARMSTEAD, Christopher H. Geothermal Energy Its Past, Present and Future Contributions to the Energy Needs of Man. E & FN Spon Ltd.
توثيق جمعية اللغة المعاصرة MLA (الطبعة الثامنة)ARMSTEAD, Christopher H. Geothermal Energy Its Past, Present and Future Contributions to the Energy Needs of Man. E & FN Spon Ltd.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.