@article{AhtiStenroosFilho1993,
  author    = {Teuvo Ahti and Soili Stenroos and Lauro Xavier Filho},
  title     = {The lichen family Cladoniaceae in Paraiba, Pernambuco and Sergipe, Northeast Brazil},
  journal   = {Tropical bryology},
  number    = {7},
  pages     = {55 -- 70},
  year      = {1993},
}