Search for: [Subject and Keywords = periodicals] OR [Subject and Keywords = ornithology] OR [Subject and Keywords = Poland] OR [Subject and Keywords = birds] OR [Subject and Keywords = Ptaki \-\- czasopisma \[KABA\]] OR [Subject and Keywords = Czasopisma naukowe \-\- Polska \-\- 20 w. \[KABA\]] OR [Subject and Keywords = Czasopisma polskie \-\- 20 w. \[KABA\]] OR [Subject and Keywords = Ornitologia \-\- czasopisma \[KABA\]] OR [Title = Acta Ornithologica Musei Zoologici Polonici \; t. 2 \- Spis treści] OR [Title = Acta Ornithologica Musei Zoologici Polonici \; t. 2 \- Spis treści]