CREATE TABLE paperfield (fieldid INT, paperid INT)
CREATE TABLE paperkeyphrase (paperid INT, keyphraseid INT)
CREATE TABLE journal (journalid INT, journalname VARCHAR)
CREATE TABLE cite (citingpaperid INT, citedpaperid INT)
CREATE TABLE dataset (datasetid INT, datasetname VARCHAR)
CREATE TABLE writes (paperid INT, authorid INT)
CREATE TABLE paperdataset (paperid INT, datasetid INT)
CREATE TABLE keyphrase (keyphraseid INT, keyphrasename VARCHAR)
CREATE TABLE author (authorid INT, authorname VARCHAR)
CREATE TABLE venue (venueid INT, venuename VARCHAR)
CREATE TABLE field (fieldid INT)
CREATE TABLE paper (paperid INT, title VARCHAR, venueid INT, year INT, numciting INT, numcitedby INT, journalid INT)

Information Extraction publications
SELECT DISTINCT paper.paperid FROM keyphrase, paper, paperkeyphrase WHERE keyphrase.keyphrasename = 'Information Extraction' AND paperkeyphrase.keyphraseid = keyphrase.keyphraseid AND paper.paperid = paperkeyphrase.paperid
SELECT DISTINCT "paper"."paperid" FROM "keyphrase" JOIN "paperkeyphrase" ON "keyphrase"."keyphraseid" = "paperkeyphrase"."keyphraseid" JOIN "paper" ON "paper"."paperid" = "paperkeyphrase"."paperid" WHERE "keyphrase"."keyphrasename" = 'Information Extraction'