E. Y. & A. G. T. N. Noel Kok Hwee Chia, “An Analysis of Verb Pattern Errors in Active-Passive/Passive-Active Sentence Transformation in English made by Upper Primary Singaporean & Malaysian Chinese Children with Specific Language Impairment”, JAASEP, vol. 5, no. 2, pp. 96–141, Jun. 2010, doi: 10.64546/jaasep.108.