A Note on the Translation of SQL to Tuple Calculus.

http://doi.acm.org/10.1145/382274.382398 db/journals/sigmod/Gogolla90.html Martin Gogolla A Note on the Translation of SQL to Tuple Calculus. 18-22 sigmodR/19-1/P018.pdf 1990 19 SIGMOD Record 1 db/journals/sigmod/sigmod19.html#Gogolla90