Tufan, A., and M. Yucel. “Accuracy and Reliability of Free Hand C7 Pedicle Screws in Posterior Cervical Fixation”. Annals of Medical Research, vol. 30, no. 8, Aug. 2023, pp. 939-44, http://www.annalsmedres.org/index.php/aomr/article/view/4492.