Terry A. Halpin, Henderik Alex Proper. Subtyping and Polymorphism in Object-Role Modelling. Data \& Knowledge Engineering, 15(3):251-281, 1995. [doi]
@article{HalpinP95:0,
title = {Subtyping and Polymorphism in Object-Role Modelling},
author = {Terry A. Halpin and Henderik Alex Proper},
year = {1995},
doi = {10.1016/0169-023X(95)00005-D},
url = {http://dx.doi.org/10.1016/0169-023X(95)00005-D},
tags = {meta-model, object-role modeling, subtyping, Meta-Environment, meta-objects},
researchr = {https://researchr.org/publication/HalpinP95%3A0},
cites = {0},
citedby = {0},
journal = {Data \& Knowledge Engineering},
volume = {15},
number = {3},
pages = {251-281},
}