LeeJ.-H., KimS.-Y., ChoD.-H., and SungH.-C. “Nest Entry Shape Change May Cause Nest Abandonment in Urban Cavity-Nesting Species: a Case Study of the Tree Sparrow Passer Montanus”. Acta Zoologica Academiae Scientiarum Hungaricae, Vol. 69, no. 1, Feb. 2023, pp. 63-72, doi:10.17109/AZH.69.1.63.2023.