Otterbeck, A., Dale, S., Lindén, A., & Marthinsen, G. (2013). A male Reed Warbler and Marsh Warbler hybrid (Acrocephalus scirpaceus × A. palustris) in Norway documented with molecular methods. Ornis Norvegica, 36, 6–13. https://doi.org/10.15845/on.v36i0.351