Investigating Health Impacts of Natural Resource Extraction Projects in Burkina Faso, Ghana, Mozambique, and Tanzania: Protocol for a Mixed Methods Study. - Farnham A; Cossa H; Dietler D; Engebretsen R; Leuenberger A; Lyatuu I; Nimako B; Zabre HR; Brugger F; Winkler MS (JMIR research protocols, 2020)