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Bosworth (1978), p. 1067. (EN) Clifford E. Bosworth, K̲h̲wārazm-S̲h̲āhs, in Emeri Johannes van Donzel, B. Lewis, Ch. Pellat e Clifford E. Bosworth, The Encyclopaedia of Islam, IV: Iran-Kha, New Edition, Leida, E.J. Brill, OCLC758278456.
Cahen (1960), p. 1051. (EN) Cl. Cahen, Barkyārūḳ, in H.A.R. Gibb, J.H. Kramers, E. Lévi-Provençal e J. Schacht, The Encyclopaedia of Islam, I: A-B, New Edition, Leida, E.J. Brill, 1960, pp. 1051-1053, OCLC495469456.
Bosworth (1978), p. 1067. (EN) Clifford E. Bosworth, K̲h̲wārazm-S̲h̲āhs, in Emeri Johannes van Donzel, B. Lewis, Ch. Pellat e Clifford E. Bosworth, The Encyclopaedia of Islam, IV: Iran-Kha, New Edition, Leida, E.J. Brill, OCLC758278456.