@article{article, title = {{Metalevel relationship cardinalities}}, url = {{}}, year = {{1999}}, month = {{1}}, author = {{Henderson-Sellers B and Graham IM}}, volume = {{12}}, journal = {{JOURNAL OF OBJECT-ORIENTED PROGRAMMING}}, issue = {{1}}, pages = {{51-58}}, note = {{Accessed on 2024/12/22}}}