Kalinski, A., Markowski, M., Banbura, M., Mikus, W., Skwarska, J., Wawrzyniak, J., Gladalski, M., Zielinski, P. and Banbura, J. (2011) “Weak correlation between haemoglobin concentration and haematocrit of nestling Great Tits Parus major and Blue Tits P. caeruleus”, Ornis Fennica, 88(4), pp. 234–240. doi: 10.51812/of.133787.