Martin Grohe, György Turán. Learnability and Definability in Trees and Similar Structures. Theory Comput. Syst., 37(1):193-220, 2004. [doi]
@article{GroheT04,
title = {Learnability and Definability in Trees and Similar Structures},
author = {Martin Grohe and György Turán},
year = {2004},
doi = {10.1007/s00224-003-1112-8},
url = {http://dx.doi.org/10.1007/s00224-003-1112-8},
researchr = {https://researchr.org/publication/GroheT04},
cites = {0},
citedby = {0},
journal = {Theory Comput. Syst.},
volume = {37},
number = {1},
pages = {193-220},
}