S. Poortman and P. Sloep, Educational models: A case study into transferability of didactical structure in a complex learning object (Learning objects in practice 3). Utrecht, The Netherlands: Stichting Digitale Universiteit, 2006.

J. Schoonenboom, A Model for Determining the Size of Learning Objects, Sixth IEEE International Conference on Advanced Learning Technologies (ICALT'06), pp.46-50, 2006.
DOI : 10.1109/ICALT.2006.1652362

URL : https://hal.archives-ouvertes.fr/hal-00190720

J. Schoonenboom, B. Emans, and J. En-meijer, Choosing for learning objects: The possible deployment of learning objects with eight educational ambitions of Dutch institutions of higher education (Learning objects in practice 1), 2006.

D. Wiley, RIP-ping on Learning Objects, 2006.