Ghani, Fazal, et al. “The Effect of Mouth Remaining Open or Close on the Depth of Mandibular Alveolo-Buccal Vestibule During Impression Recording”. Journal of Pakistan Prosthodontics Association, vol. 1, no. 1, Mar. 2013, pp. 12-20, https://www.jppa.pk/jppa/article/view/6.