Gjorgjiev, M. and Petkovski, D. (1994) “Content of total and easy soluble cobalt in the vertisols of Kratovo-Zletovo volcanic region”, Macedonian Journal of Ecology and Environment, 2(2), pp. 37–41. Available at: https://mjee.org.mk/index.php/mjee/article/view/22 (Accessed: 8May2024).