Published in Journal of The Arnold Arboretum, in 1952, in volume 33, issue 4, pages 299-366

Published in Journal of The Arnold Arboretum, in 1952, in volume 33, issue 2, pages 166-178

Published in Journal of The Arnold Arboretum, in 1952, in volume 33, issue 2, pages 188-191

Published in Journal of The Arnold Arboretum, in 1952, in volume 33, issue 2, pages 192-198

Published in Journal of The Arnold Arboretum, in 1952, in volume 33, issue 3, pages 296-298

Published in Journal of the Arnold Arboretum, in 1952, in volume 33, pages 62-78

Published in Journal of the Arnold Arboretum, in 1952, in volume 33, pages 91-95