Links between papers, authors, and affiliations/institutions. NOTE: It is possible to have multiple rows with same (PaperId, AuthorId, AffiliationId) when an author is associated with multiple affiliations. (mag/PaperAuthorAffiliations.txt)
FOREIGN KEY REFERENCES Papers.PaperId
FOREIGN KEY REFERENCES Authors.AuthorId
FOREIGN KEY REFERENCES Affiliations.AffiliationId
1-based author sequence number. 1: the 1st author listed on paper, 2: the 2nd author listed on paper, etc.