Nayak, B. B., T. Dash, and B. K. Mishra. “Purple Coloured Natural Ruby: X-Ray Photoelectron Spectroscopy, X-Ray Diffraction, X-Ray Tomography and Other Microstructural Characterizations”. International Journal of Sciences: Basic and Applied Research (IJSBAR), vol. 25, no. 2, Feb. 2016, pp. 94-114, https://gssrr.org/index.php/JournalOfBasicAndApplied/article/view/5123.