Não informado. (1926). Bulletin of the National Association of Secondary School Principals. National Association of Secondary School Principals.
শিকাগো স্টাইল (17 তম সংস্করণ) উদ্ধৃতিNão informado. Bulletin of the National Association of Secondary School Principals. Washington: National Association of Secondary School Principals, 1926.
M.L.A (8 ম সংস্করণ) উদ্ধৃতিNão informado. Bulletin of the National Association of Secondary School Principals. National Association of Secondary School Principals, 1926.
সতর্কবাণী: সাইটেশন সবসময় 100% নির্ভুল হতে পারে না.