Integrating resources are distinct in that they change over time in such a way that their previous content is replaced with updated content. This study examines how integrating resources can be modeled using the entities and relationships of the IFLA Library Reference Model (LRM) and clarifies how they can be identified. While monographs have been extensively analyzed, integrating resources have received very little attention. Applying the model unmodified to integrating resources is neither practical nor theoretically sound. With the addition of two proposed relationships, the model can be extended to accommodate the diachronic relationship intrinsic between expressions and manifestations exhibited by integrating resources.