Ligna, Cedric, et al. “Petrology, Geochemistry and Geodynamic Significance of the Mafic and Ultramafic Rocks of the Akou (Okondja Basin, Gabon)”. European Scientific Journal, ESJ, vol. 14, no. 12, Apr. 2018, p. 347, doi:10.19044/esj.2018.v14n12p347.