@article{oliveira:2006:cp,
    author = {{Oliveira e Silva}, Tom{\'a}s},
     title = {Computing $\pi(x)$: The combinatorial method},
   journal = {Revista do {DETUA}},
      year = {2006},
    volume = {4},
    number = {6},
     pages = {759–768},
     enote = {Online fulltext contains postpublication annotations.},
     links = {\URL[FullText]{http://www.ieeta.pt/~tos/bib/5.4.pdf}}}