Images used in the "Timeframes" pages are reproduced as fair use, and their sources are cited here with URLs.

Timeframe1.htm,     http://www.boatnerd.com/pictures/images/sunrise.jpg

Timeframe2.htm,     http://seds.lpl.arizona.edu/messier/browser/brm045.html

http://www.macalester.edu/~sisk/mind/shakespeare.jpg

Timeframe3.htm,    http://gyroscope.txo.hu/planetaries/planetaries.htm

http://www.belmontnc.4dw.net/AstroBio.htm

Timeframe4.htm,    http://www.seds.org/messier/m/m026.html

http://www.upenn.edu/museum/Games/cuneiform.html

Timeframe5.htm,    http://www.noao.edu/image_gallery/html/im0575.html

http://www.museum.state.il.us/exhibits/larson/ISM_mastodon_mount.html

Timeframe6.htm,    http://pulsar67.free.fr/Messier/m5.jpg

http://www.culture.gouv.fr/culture/arcnat/lascaux/en/

Timeframe7.htm,    http://homepages.wmich.edu/~korista/stargal-images/m31-noao_uvbri_hao3.jpg

http://lithiccastinglab.com/gallery-pages

Timeframe8.htm,     http://antwrp.gsfc.nasa.gov/apod/ap030417.html

Timeframe9.htm,     http://www.jpl.nasa.gov/releases/2003/30.cfm

http://www.eso.org/outreach/press-rel/pr-2000/phot-07-00.html

Timeframe10.htm,   http://sprite.phys.ncku.edu.tw/~astrolab/mirrors/apod_e/ap001113.html

http://www.fossilmall.com/Science/About_Trilobites.htm

Timeframe11.htm,   http://www.rdcrisp.darkhorizons.org/images/abell1656.jpg

http://www.ucmp.berkeley.edu/arthropoda/trilobita/dalmanites.jpg

http://www.ucmp.berkeley.edu/historyoflife/mysteries/mystery15/mystery15.html

Timeframe12.htm,   http://www.astr.ua.edu/keel/agn/q0957.html