Nguembock, B.; Fjeldså, J.; Couloux, A.; Pasquet, E. (2008). "Phylogeny of Laniarius: Molecular data reveal L. liberatus synonymous with L. erlangeri and 'plumage coloration' as unreliable morphological characters for defining species and species groups". Molecular Phylogenetics and Evolution. 48 (2): 396–407. doi:10.1016/j.ympev.2008.04.014. PMID18514549.
Nguembock, B.; Fjeldså, J.; Couloux, A.; Pasquet, E. (2008). "Phylogeny of Laniarius: Molecular data reveal L. liberatus synonymous with L. erlangeri and 'plumage coloration' as unreliable morphological characters for defining species and species groups". Molecular Phylogenetics and Evolution. 48 (2): 396–407. doi:10.1016/j.ympev.2008.04.014. PMID18514549.