1. Mississippi Valley type lead zinc deposits;Leach,1993
2. A Deposit Model for Mississippi Valley-Type Lead Zinc Ores: Chap. A of Mineral Deposit Models for Resources Assessment;Leach,2010
3. ZINC, Mineral Commodity Summaries,2017
4. Zinc Outlook 2018: Will Prices Continue to Rally?http://investingnews.com/daily/resource-investing/base-metals investing/zinc-investing/zinc-outlook/
5. European Commissionhttp://www.catalysiscluster.eu/wp/wp-content/uploads/2015/05/2014_Critical-raw-materials-for-the-EU-2014.pdf