Rajchard, Josef, Josef Navrátil, Ryan J. Frazier, Eva Ježková, és Kateřina Marková. 2020. „Comparison of Spring and Summer Clutches of Great Crested Grebes (Podiceps Cristatus)”. Acta Zoologica Academiae Scientiarum Hungaricae 66 (4):393–401. https://doi.org/10.17109/AZH.66.4.393.2020.