Peter P. Chen Entity-Relationship Diagrams and English Sentence Structure. 13-14 1979 ER db/conf/er/er79.html#Chen79a conf/er/79 db/conf/er/Chen79a.html er79/ER79-P013.pdf journals/tods/Chen76 conf/afips/Chen77 ... conf/db-workshops/Chen78 ... conf/er/SantosNF79 conf/er/ScheuermannSW79 journals/cl/SchiffnerS79