Trees in the city - perception and aesthetic expression / Erwin Frohmann .
In: Plants in urban areas and landscape [114 s.]. -- Nitra : Slovak University of Agriculture, 2020. -- ISBN 978-80-552-2146-5 (brož.). -- S. 3-9
https://dx.doi.org/10.15414/PUAL/2020.3-9 http://www.slpk.sk/eldo/2020/dl/9788055221649/files/frohmann.html .