Sepúlveda Delgado, O., González Gutiérrez, N. R., & Aldana Bermúdez, E. (2017). Epistemological Study of the Object Group: A Piagetian Perspective in the Light of The Onto- Semiotic Approach to Mathematics Cognition. Universidad Pedagógica y Tecnológica de Colombia.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रSepúlveda Delgado, Omaida, Nelsy Rocío González Gutiérrez, और Eliécer Aldana Bermúdez. Epistemological Study of the Object Group: A Piagetian Perspective in the Light of The Onto- Semiotic Approach to Mathematics Cognition. Universidad Pedagógica y Tecnológica de Colombia, 2017.
एमएलए (9वां संस्करण) प्रशस्ति पत्रSepúlveda Delgado, Omaida, et al. Epistemological Study of the Object Group: A Piagetian Perspective in the Light of The Onto- Semiotic Approach to Mathematics Cognition. Universidad Pedagógica y Tecnológica de Colombia, 2017.