Tulgan, B., & Chamberlain, M. (2020). The art of being indispensable at work: Win influence, beat overcommitment, and get the right things done (Unabridged.). Ascent Audio.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Tulgan, Bruce, و Mike Chamberlain. The Art of Being Indispensable at Work: Win Influence, Beat Overcommitment, and Get the Right Things Done. Unabridged. Rego Park: Ascent Audio, 2020.
توثيق جمعية اللغة المعاصرة MLA (الطبعة الثامنة)Tulgan, Bruce, و Mike Chamberlain. The Art of Being Indispensable at Work: Win Influence, Beat Overcommitment, and Get the Right Things Done. Unabridged. Ascent Audio, 2020.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.