Mark A. Roth Henry F. Korth Abraham Silberschatz Extended Algebra and Calculus for Nested Relational Databases. 389-417 TODS13/P389.PDF 1988 13 ACM Trans. Database Syst. 4 db/journals/tods/tods13.html#RothKS88 http://doi.acm.org/10.1145/49346.49347 db/journals/tods/RothKS88.html conf/pods/AbiteboulB84 conf/vldb/ArisawaMM83 ... journals/cacm/Codd70 persons/Codd72 ... journals/jcss/FischerSTG85 ... conf/pods/FischerG84 conf/stacs/FischerG85 journals/sigmod/Furtado81 conf/sigmod/FurtadoK77 journals/jacm/HullY84 journals/jacm/Jacobs82 ... ... conf/pods/JaeschkeS82 ... journals/jacm/Klug82 ... conf/pods/KuperV84 conf/vldb/Makinouchi77 ... ... journals/tods/OzsoyogluY87 ... conf/sigmod/RothK87 journals/is/RothKB87 ... conf/fodo/Schek85 conf/vldb/SchekP82 journals/is/SchekS86 journals/tods/SmithS77 books/cs/Ullman82