David Machin/ Michael J. Campbell/ Stephen J. Walters
(1)
Eric A. Hanushek (EDT)/ Stephen J. Machin (EDT)/ Ludger Woessmann (EDT)
(1)
Eric A. Hanushek (EDT)/ Stephen Machin (EDT)/ Ludger Woessmann (EDT)
(1)
Erik A. Hanushek (EDT)/ Stephen Machin (EDT)/ Ludger Woessmann (EDT)
(1)
Lee Elliot Major , Stephen Machin
(1)
Philip J. Cook, Stephen Machin, Olivier Marie, Giovanni Mastrobuoni
(1)
Stephen Machin,Anna F. Vignoles
(1)