Charles Welty David W. Stemple Human Factors Comparison of a Procedural and a Nonprocedural Query Language. 626-649 TODS6/P626.PDF 1981 6 ACM Trans. Database Syst. 4 db/journals/tods/tods6.html#WeltyS81 http://doi.acm.org/10.1145/319628.319656 db/journals/tods/WeltyS81.html ... ... journals/cacm/AstrahanC75 journals/cacm/BoyceCKH75 ... ... conf/sigmod/ChamberlinB74 journals/cacm/Codd70 conf/sigmod/Codd71 persons/Codd72 books/aw/Date77 ... conf/sigmod/FurtadoK77 journals/tse/GannonH75 ... ... ... ... ... ... ... conf/ldrs/Love77 ... ... ... journals/tse/Reisner77 ... ... ... ... ... ... journals/cacm/ShneidermanMMH77 ... ... conf/vldb/StonebrakerR77 ... ... ... ... ... ... ...