1. Teixeira LAV, Silva RG (2015) System and process for selective rare earth extraction with sulphur recovery. Patent US 2015/0329940 A1
2. Simandl GJ (2014) Geology and market-dependent significance of rare earth element resources. Miner Deposita 49:889–904
3. Simandl GJ (2012) Geology and economic significance of current and future rare earth element sources. Conference of metallurgists-rare earth elements. pp 15–30
4. Verbaan N, Bradley K, Brown J, Mackie S (2015) A review of hydrometallurgical flowsheets considered in current REE projects. British Columbia Ministry of Energy and Mines, British Columbia Geological Survey Paper 2015-3 pp 147–162
5. Sadri F, Nazari AM, Ghahreman A (2017) A review on the cracking, baking and leaching processes of rare earth element concentrates. J Rare Earths 35:739–752. https://doi.org/10.1016/S1002-0721(17)60971-2