Returns the value of ReferencesElements attribute. This attribute represents a set of spatial reference relationships, that holds those elements, which are referenced, but not contained, within this element of the project spatial structure.

• The spatial reference relationship, established by IfcRelReferencedInSpatialStructure, is not required to be an hierarchical relationship, i.e. each element can be assigned to 0, 1 or many spatial structure elements.
• IFC2x3 CHANGE: The inverse attribute has been added with upward compatibility for file-based exchange.