Potrykus, Marcin. “ASSESSMENT OF GOLD AND OR CRUDE OIL AS INVESTMENTS FOR PORTFOLIO DIVERSIFICATION. A WARSAW STOCK EXCHANGE CASE STUDY”. Acta Scientiarum Polonorum. Oeconomia 18, no. 4 (December 30, 2019): 77–84. Accessed April 7, 2025. https://aspe.sggw.edu.pl/article/view/183.