Leakey, Roger; Shackleton, Sheona; Du Plessis, Pierre (2005). »Domestication potential of Marula (Sclerocarya birrea subsp caffra) in South Africa and Namibia: 1. Phenotypic variation in fruit traits«. Agroforestry Systems. 64 (1): 25–35. Bibcode:2005AgrSy..64...25L. doi:10.1007/s10457-005-2419-z. S2CID21601141.
»Protected Trees«(PDF). Department of Water Affairs and Forestry, Republic of South Africa. 3. maj 2013. Arhivirano iz prvotnega spletišča(PDF) dne 5. julija 2010.
Leakey, Roger; Shackleton, Sheona; Du Plessis, Pierre (2005). »Domestication potential of Marula (Sclerocarya birrea subsp caffra) in South Africa and Namibia: 1. Phenotypic variation in fruit traits«. Agroforestry Systems. 64 (1): 25–35. Bibcode:2005AgrSy..64...25L. doi:10.1007/s10457-005-2419-z. S2CID21601141.
Leakey, Roger; Shackleton, Sheona; Du Plessis, Pierre (2005). »Domestication potential of Marula (Sclerocarya birrea subsp caffra) in South Africa and Namibia: 1. Phenotypic variation in fruit traits«. Agroforestry Systems. 64 (1): 25–35. Bibcode:2005AgrSy..64...25L. doi:10.1007/s10457-005-2419-z. S2CID21601141.
»Protected Trees«(PDF). Department of Water Affairs and Forestry, Republic of South Africa. 3. maj 2013. Arhivirano iz prvotnega spletišča(PDF) dne 5. julija 2010.