Gottlob, G., Kappel, G., & Schrefl, M. (1995). The Evolving Algebra Semantics of Class and Role Hierarchies. Springer.
芝加哥风格引文Gottlob, G., G. Kappel, 与 M. Schrefl. The Evolving Algebra Semantics of Class and Role Hierarchies. Springer, 1995.
MLA引文Gottlob, G., et al. The Evolving Algebra Semantics of Class and Role Hierarchies. Springer, 1995.
警告：这些引文格式不一定是100％准确.