Riva, PatŽumer, Maja2025-09-242025-09-242018https://repository.ifla.org/handle/20.500.14598/6278IFLA's conceptual models for bibliographic information are maintained in two forms, entity-relationship modelling and object-oriented modelling. The two formalisms have different strengths and purposes, but the choice does not have a crucial effect on the model itself. As the models have developed in phases, the insights gained in one round of development have regularly informed and influenced the next development. This paper illustrates the influences and adaptation of ideas using examples from the most recently approved models: FRBRoo version 2.4 (2016) and IFLA LRM (2017), continuing to current work to create LRMoo.engAttribution 4.0 Internationalhttps://creativecommons.org/licenses/by/4.0/Articlehttps://2018.ifla.org/open accessIFLA Library Reference ModelIFLA LRMCIDOC Conceptual Reference ModelFRBRooLRMoo