International Telecommunication Union. General Secretariat. General telephone statistics compiled from official documents. s.n.
Цитирование в стиле Чикаго (17-е изд.)International Telecommunication Union. General Secretariat. General Telephone Statistics Compiled from Official Documents. Geneva: s.n.
Цитирование MLA (9-е изд.)International Telecommunication Union. General Secretariat. General Telephone Statistics Compiled from Official Documents. s.n.
Предупреждение: эти цитированмия не могут быть всегда правильны на 100%.