Marx, Karl.Karl Marx: Selected Writings / Karl Marx, David McLellan. — Oxford University Press, 2000. — P. 55. — «Indeed, it is not the so-called Christian state, that one that recognizes Christianity as its basis, as the state religion, and thus adopts an exclusive attitude to other religions, that is the perfected Christian state, but rather the atheist state, the ...». — ISBN 9780198782650.
Truxillo, Charles A.Periods of World History: A Latin American Perspective. — Jain Publishing Company, 2008-01-01. — P. 103. — «The Byzantine Empire, stripped of Syria, Egypt, and North Africa, became a compact Orthodox Christian state, upholding its claim to Roman universalism and constructing an Orthodox Christian commonwealth among the Slavs of the Balkans and Russia.». — ISBN 9780895818638.
Snyder, Louis Leo.Macro-nationalisms: A History of the Pan-movements : [англ.]. — Greenwood Press, 1984. — P. 129. — «Throughout the better part of the Middle Ages, elaborate attempts were made to create what was, in effect, a Pan-Christianity, an effort to unite "all" the Western Christian world into a successor state of the Roman Empire.». — ISBN 978-0-313-23191-9.
