Halim, S., Halim, F., & Effendy, S. (2020). Competitive programming 4: The lower bound of programming contests in the 2020s. Ingram content group.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Halim, Steven, Felix Halim, و Suhendry Effendy. Competitive Programming 4: The Lower Bound of Programming Contests in the 2020s. United States, UK: Ingram content group, 2020.
توثيق جمعية اللغة المعاصرة MLA (الطبعة الثامنة)Halim, Steven, et al. Competitive Programming 4: The Lower Bound of Programming Contests in the 2020s. Ingram content group, 2020.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.