Requested reference
Wiśniewski, K., Rozwałka, R. & Wesołowska, W. (2013). The first record of Hahnia difficilis Harm, 1966 (Araneae, Hahniidae) in Poland. Fragmenta Faunistica 56(1): 55-63. doi:10.3161/00159301ff2013.56.1.055 -- Show included taxa
Wiśniewski, K., Rozwałka, R. & Wesołowska, W. (2013). The first record of Hahnia difficilis Harm, 1966 (Araneae, Hahniidae) in Poland. Fragmenta Faunistica 56(1): 55-63. doi:10.3161/00159301ff2013.56.1.055 -- Show included taxa