TY - JOUR T1 - Recent changes in the presence status and numbers of ruddy shelduck (Tadorna ferruginea) in the Eastern Balkans AU - Shurulinkov, Peter AU - Daskalova, Girgina AU - Popov, Konstantin AU - Dalakchieva, Svetla AU - Tzonev, Rossen AU - Dimchev, Ivaylo AU - Ralev, Andrey JF - Historia naturalis bulgarica VL - 41 IS - 6 SP - 41 EP - 49 Y1 - 09/04/2020 PB - National Museum of Natural History (BAS) UR - https://www.nmnhs.com/historia-naturalis-bulgarica/article.php?id=000444000412020 SN - 2603-3186 ER -