Peter Buneman Shamim A. Naqvi Val Tannen Limsoon Wong Principles of Programming with Complex Objects and Collection Types. 3-48 1995 149 Theor. Comput. Sci. 1 db/journals/tcs/tcs149.html#BunemanNTW95 http://dx.doi.org/10.1016/0304-3975(95)00024-Q