Muhammad, Dost, et al. “DIAGNOSTIC ACCURACY OF GRAY-SCALE AND COLOUR DOPPLER ULTRASONOGRAPHY IN DIAGNOSING MALIGNANT THYROID NODULES: Gray-Scale and Colour Doppler USG in Thyroid Nodules”. Pakistan Armed Forces Medical Journal, vol. 66, no. 4, Aug. 2016, pp. 574-78, https://pafmj.org/PAFMJ/article/view/768.