Blom, E., Craats-Oosterwold, I. v. d., & Verhagen, J. (2013). Dummy auxiliaries in first and second language acquisition. De Gruyter Mouton.

Blom, Elma, Ineke va de Craats-Oosterwold, and Josje Verhagen. Dummy Auxiliaries in First and Second Language Acquisition. Boston: De Gruyter Mouton, 2013.

Blom, Elma, et al. Dummy Auxiliaries in First and Second Language Acquisition. De Gruyter Mouton, 2013.