Laasonen, E., and L. Laasonen. “Habitual Differences of <i>Phyllonorycter salictella</i> (Zeller, 1846 ) and <i>P. heringiella</i> ( Grönlien, 1932) (Lepidoptera: Gracillariidae) in Two Finnish Materials; A Problem Pair”. Entomologica Fennica, vol. 11, no. 3, Sept. 2000, pp. 175-81, doi:10.33338/ef.84063.