Top panel. A search with “Lander 2001 Nature” showing the Citation Sensor. The Citation Sensor shows a more relevant set of results including the paper reporting the human genome sequence. Center panel. Accession Sensor triggered by a search with GenBank Accession number X51362. The sensor provides a direct link to the sequence record. The PubMed results contain the two papers linked to the nucleotide record. Bottom panel. Accession Sensor triggered by a search with Reference Sequence accession number NM_000795. The sequence record has no linked articles in PubMed, but the sensor provides a direct link to the record in the nucleotide database.