Rivers and Streams, Britannica Educational Publishing, The Rosen Publishing Group, 2011, ISBN 978-1-61530-411-0, ... If, however, the Irtysh River is regarded as part of the main course rather than as the Ob's major tributary, the maximum length, from the source of the Black (Chorny) Irtysh in China's sector of the Altai, is 5410 km (3362 miles) ...
