Paul Lindgreen Entity Sets and their Description. 91-110 1983 ER db/conf/er/er83.html#Lindgren83 conf/er/83 db/conf/er/Lindgren83.html er83/ER83-P091.pdf conf/ifip/Bubenko80 ... ... ... ... ... conf/ifip/Lindgreen74 persons/Codd71 journals/bit/Naur82