Britton, W.E., & Zappe, M.P. 1929a Inspection of nurseries in 1928.. Bulletin of the Connecticut Agricultural Experiment Station No. 305: 689-700.

Notes: Scales mentioned include elm, elm scurfy, euonymus, juniper, Lecanium on currant, oak gall, oyster shell, pine leaf, rose, San Jose, scurfy tulip tree and West Indian Peach.