- The chr*fa and someORF.fa files were extracted from
  ftp://genome-ftp.stanford.edu/pub/yeast/sequence
  on 1 Nov 2005. -- VJC

- Only the someORF.fa and fastaEx.fa files have been kept from Biostrings 1
  (original names were someORF.fsa and fastaEx). -- H. Pages

- dm3_upstream2000.fa.gz was obtained by downloading upstream2000.fa.gz from
  http://hgdownload.soe.ucsc.edu/goldenPath/dm3/bigZips/ on 27 May 2014, and
  renaming it.

