Griswold, G.H. 1925 A study of the oyster-shell scale Lepidosaphes ulmi (L.), and one of its parasites, Aphelinus mytilaspidis Le B.. Cornell University Agricultural Experiment Station Memoir 93: 1-67.

Notes: Pt. 1, biology and morphology of two forms of this scale; Pt. 2, biology of a parasite.