1. RAMU NiCo Ltd., MCC, http://www.ramunico.com/plus/list.php?tid=240.
2. Highland Pacific Cop., http://www.highlandspacific.com/current-projects/ramu-nickel.
3. Pressure Acid Leaching of Nickel Laterites: A Review
4. Atmospheric acid leaching of nickel laterites review
5. A. Taylor, Trends in nickel-cobalt processing, ALTA 2009 Nickel/Cobalt - ALTA Metallurgical Services, Melbourne, Australia (2009).