バルト連合公国
↑ "...later an alternative proposal was advanced for a United Baltic Duchy under Duke Adolf Friedrich of Mecklenburg" p. 48 The Baltic States: The Years of Independence By Georg von Rauch ISBN 0903983001
↑ This "Landesrat" on April 12, 1918, decided to beg the King of Prussia and German Kaiser to accept the throne of the Grand Duchy of Livonia Bilmanis, Alfreds (1945). Baltic Essays. The Latvian Legation,. https://books.google.com/bkshp?hl=en&tab=wp&q=%22This%20%22Landesrat%22%20on%20April%2012%2C%201918%2C%20decided%20to%20beg%20the%20King%20of%20Prussia%20and%20German%20Kaiser%20to%20accept%20the%20throne%20of%20the%20Grand%20Duchy%20of%20Livonia%22
↑ Roeder, Philip (2007).