Z. Q. Zhang and  Y. Zhang and  D. L. Li,  The Flotation Device Designed to Treat Phosphate Rock.   journal   = {International Journal of Geological and Environmental Engineering}, [online]. World Academy of Science, Engineering and Technology.
    February 2019, vol. 147(3). 129 - 132
    [viewed 04 April 2020]. Available from: https://publications.waset.org/pdf/10010120.