(EL) Ioannis Stouraitis, Σκληροί, in Encyclopaedia of the Hellenic World, Asia Minor, Atene, Foundation of the Hellenic World, 10 ottobre 2003.
worldcat.org
(EN) A. P. Kazhdan, Alice-Mary Maffry Talbot e Anthony Cutler, Skleros, in The Oxford dictionary of Byzantium, Oxford University Press, 1991, ISBN0-19-504652-8, OCLC22733550. URL consultato l'8 luglio 2022.