Rock, Joseph Francis Charles, 1884-1962.(Lancaster, Pa. : Published in cooperation with the Botanical Society of America by the Brooklyn Botanic Gardens, 1917-12)
Rock, Joseph Francis Charles, 1884-1962.(Lancaster, Pa. : Published in cooperation with the Botanical Society of America by the Brooklyn Botanic Gardens, 1918-05)
Rock, Joseph Francis Charles, 1884-1962.(Lancaster, Pa. : Published in cooperation with the Botanical Society of America by the Brooklyn Botanic Gardens, 1919-02)
Rock, Joseph Francis Charles, 1884-1962.(Lancaster, Pa. : Published in cooperation with the Botanical Society of America by the Brooklyn Botanic Gardens, 1919-05)