Baiyegunhi, Christopher; Liu, Kuiwu; Gwavava, Oswald (28 oktober 2017). ”Modal composition and tectonic provenance of the sandstones of Ecca Group, Karoo Supergroup in the Eastern Cape Province, South Africa”. Open Geosciences 9 (1): sid. 491–508. doi:10.1515/geo-2017-0038. ISSN2391-5447.
Baiyegunhi, Christopher; Liu, Kuiwu; Gwavava, Oswald (28 oktober 2017). ”Modal composition and tectonic provenance of the sandstones of Ecca Group, Karoo Supergroup in the Eastern Cape Province, South Africa”. Open Geosciences 9 (1): sid. 491–508. doi:10.1515/geo-2017-0038. ISSN2391-5447.