Twin directories of sierra:

[DIR]  ftp://ftp.sierra.com/pub/sierra/
[DIR]  ftp://ftp.rootsweb.com/pub/usgenweb/nm/sierra/
[DIR]  ftp://ftp.wsisiz.edu.pl/pub/pc/sierra/
[DIR]  ftp://mask-student.wsisiz.edu.pl/pub/pc/sierra/
[DIR]  ftp://ftp.mega-tokyo.com/pub/sierra/
[DIR]  ftp://ftp.nsu.ru/mirrors/ftp.jinr.dubna.su/pub/games/sierra/
[DIR]  ftp://ftp.stben.net/pub/sierra/
[DIR]  ftp://ftp.de.scene.org/pub/music/artists/sierra/
[DIR]  ftp://ftp.scene.org/pub/music/artists/sierra/
[DIR]  ftp://ftp.de.scene.org/pub/music/groups/rbi/guest/sierra/
[DIR]  ftp://ftp.scene.org/pub/music/groups/rbi/guest/sierra/
[DIR]  ftp://ftp.gathering.org/scene.org/music/artists/sierra/
[DIR]  ftp://ftp.gathering.org/scene.org/music/groups/rbi/guest/sierra/
[DIR]  ftp://ftp.cgd.ucar.edu/pub/acacia/usgs/sierra/
[DIR]  ftp://ftp.mcs.anl.gov/pub/neos/netlib/sierra/