Koop, J., & Rutberg, J. (2016). Training essentials for ultrarunning: How to train smarter, race faster, and maximize your ultramarathon performance. VeloPress.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Koop, Jason, و Jim Rutberg. Training Essentials for Ultrarunning: How to Train Smarter, Race Faster, and Maximize Your Ultramarathon Performance. Boulder, Colorado: VeloPress, 2016.
توثيق جمعية اللغة المعاصرة MLA (الطبعة الثامنة)Koop, Jason, و Jim Rutberg. Training Essentials for Ultrarunning: How to Train Smarter, Race Faster, and Maximize Your Ultramarathon Performance. VeloPress, 2016.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.