चक्रवर्ती उत्‍पल. गणित, पाठ्यपुस्तक और शिक्षक. Voices of Teachers and Teacher Educators, [S. l.], v. 5, n. 1, p. p. 32–34, 2016. Disponível em: http://ejournals.ncert.gov.in/index.php/vtte/article/view/137. Acesso em: 16 jun. 2025.