Sidek, N. F. (2013). Types of muscle activated during crunch performed traditionally and on stability ball / Nurul Fizan Sidek.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Sidek, Nurul Fizan. Types of Muscle Activated During Crunch Performed Traditionally and on Stability Ball / Nurul Fizan Sidek. 2013.
توثيق جمعية اللغة المعاصرة MLA (الطبعة الثامنة)Sidek, Nurul Fizan. Types of Muscle Activated During Crunch Performed Traditionally and on Stability Ball / Nurul Fizan Sidek. 2013.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.