Is it farther or further?
1951 (adj.), 1963 (n.), in reference to the sort of Marxist-Leninist communist doctrines invented by Chairman Mao Tse-tung of China.
The doctrines of Mao Zedong, most notably the doctrine that a continuous revolution is necessary if the leaders of a communist state are to be kept in touch with the people. (See Great Proletarian Cultural Revolution.)