1. Advanced Metallurgical Group (2013) AMG advanced metallurgical group N.V. announces tantalum mineral resources update at Volte Grande mine. http://www.amg-nv.com/Investors/Press-Releases/Press-Release-Details/2013/AMG-Advanced-Metallurgical-Group-NV-Announces-Tantalum-Mineral-Resources-Update-at-Volte-Grande-Mine/default.aspx . Accessed 11 Dec 2013
2. Alkane Resources Ltd. (2013) Dubbo project overview. http://www.alkane.com.au/index.php/projects/current-projects/dubbo . Accessed 11 Dec 2013
3. Allsopp HL, Hargraves RB (1985) Rb–Sr ages and palaeomagnetic data for some Angolan alkaline intrusives. Trans Geol Soc S Afr 88:295–299
4. Anglo American PLC (2014) Annual report 2013. Anglo American PLC. London, UK. http://www.angloamerican.com/%7E/media/Files/A/Anglo-American-Plc/reports/annual-report-2013/annual-report2013.pdf . Accessed 16 Jun 2014
5. Anhaeusser CR (1976) Archean metallogeney in Southern Africa. Econ Geol 71:16–45