Biblical scholar Harold Hoehner, surveying 279 commentaries written between 1519 and 2001, found that 54% favored Pauline authorship, 39% concluded against Pauline authorship and 7% remained uncertain. Norman Perrin and Dennis C. Duling found that of six authoritative scholarly references, "four of the six decide for pseudonymity, and the other two (Peake's Commentary on the Bible and the Jerome Biblical Commentary) recognize the difficulties in maintaining Pauline authorship. Indeed, the difficulties are insurmountable." Bible scholar Raymond E. Brown asserts that about 80% of critical scholarship judges that Paul did not write Ephesians.