Jones; Odendaal, Ehrlich (January 1986). "Evidence against the spermatophore as paternal investment in checkerspot butterflies (Euphydras: Nymphalidae)". American Midland Naturalist. 116 (1): 1–6. doi:10.2307/2425932. JSTOR2425932.
Jones; Odendaal, Ehrlich (January 1986). "Evidence against the spermatophore as paternal investment in checkerspot butterflies (Euphydras: Nymphalidae)". American Midland Naturalist. 116 (1): 1–6. doi:10.2307/2425932. JSTOR2425932.
Svärd, L. (1985). "Paternal investment in a monandrous butterfly, Pararge aegeria". Oikos. 45 (1): 66–70. doi:10.2307/3565223. JSTOR3565223.