Paper  doi  bibtex   

@article{DBLP:journals/mst/GroheT04,
  author    = {Martin Grohe and
               Gy{\"{o}}rgy Tur{\'{a}}n},
  title     = {Learnability and Definability in Trees and Similar Structures},
  journal   = {Theory Comput. Syst.},
  volume    = {37},
  number    = {1},
  pages     = {193--220},
  year      = {2004},
  url       = {https://doi.org/10.1007/s00224-003-1112-8},
  doi       = {10.1007/s00224-003-1112-8},
  timestamp = {Thu, 08 Jun 2017 01:00:00 +0200},
  biburl    = {https://dblp.org/rec/journals/mst/GroheT04.bib},
  bibsource = {dblp computer science bibliography, https://dblp.org}
}