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

papers on mechanical turk experiments
SELECT DISTINCT paper.paperid FROM keyphrase, paper, paperkeyphrase WHERE keyphrase.keyphrasename = 'mechanical turk' 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" = 'mechanical turk'