1. Pearce, S. C. (1952). Studies in the measurement of apple trees. I. The use of trunk girths to estimate tree size.Rep. E. Mailing Res. Sta. for 1951, 101–4.
2. Preston, A. P. (1953). Five new apple rootstocks.Rep. E. Mailing Res. Sta. for 1952, 169–70.