history of early ottoman bulgaria - References

• DEVŞİRME USULÜ - ACEMİ OĞLANLAR OCAĞI MÜESSESESİ - article about devshirme method (in Turkish)
• "Dervisirme" in "Encyclopaedia of the Orient"
• website on the Ottoman empire - original German version; here its Janissary page (to be further exploited)
• Papoulia, B.D., _Ursprung und Wesen der “knabenlese” im Osmanischen Reich_ . München, 1963 (in German, title means 'origin and nature of the 'boy harvest' in the Ottoman Empire)