A. I. Alajtal and H. G. M. Edwards and M. A. Elbagermi , Vibratinal Spectroscopic Identification of Beta-Carotene in Usnic Acid and PAHs as a Potential Martian Analogue. journal = {International Journal of Bioengineering and Life Sciences}, [online]. World Academy of Science, Engineering and Technology. January 2014, vol. 85(1). 50 - 53 [viewed 27 April 2024]. Available from: https://publications.waset.org/pdf/9997244.