Tests of Additional Conditional Moment Restrictions
Paulo Parente, Richard J. Smith
Journal of Econometrics, vol. 200, 2017, p. 1-16.

GEL Statistics under Weak Identification
Joaquim Ramalho, Patrik Guggenberger, Richard J. Smith
Journal of Econometrics, vol. 170, 2012, p. 331-349.