Nixon, P. H., et al. “Graphite Pseudomorphs After Diamond in the Eclogite-Peridotite Massif of Beni Bousera, Morocco and a Review of Anomalous Diamond Occurrences”. International Kimberlite Conference: Extended Abstracts, vol. 4, no. 1, Sept. 1986, pp. 412-4, doi:10.29173/ikc1187.