Atmospheric carbon dioxide record from Mauna Loa; KeelingC. D. and WhorfT. P.; Carbon Dioxide Research Group, Scripps Institution of Oceanography, http://cdiac.ornl.gov/trends/co2/sio-mlo.htm.
14.
Reference Gas Preparation and Calibration; NOAA Technical Memorandum ERL-14 CMDL/Carbon Cycle Greenhouse Gases Group Standards Preparation And Stability Duane Kitzis, Conglong Zhao; NOAA 1999 http://www.cmdl.noaa.gov/ccgg/refgases/airstandard.html und.
15.
ZhaoC.L.TansP.P., and ThoningK.W., A high precision manometric system for absolute calibrations of CO2 in dry air, Journal of Geophysical Research, 102 (D 5), 5885, 1997.
16.
A Brief History of Atmospheric CO2 Measurements and Their Impact on Thoughts about Environmental Change; Dr. Charles D. Keeling speech: Winner of the Second Blue Planet Prize (1993); http://www.af-info.or.jp/eng/honor/bppcl_e/e1993keeling.txt.
17.
KeelingC. D., 1958. The concentration and isotopic abundances of atmospheric carbon dioxide in rural areas, Geochim Cosmochim Acta. 13: 322–334.
Exchanges of Atmospheric CO2 and 13CO2 with the Terrestrial Biosphere and Oceans from 1978 to 2000. Global Aspects Charles D. Keeling1, Stephen C. Piper1, Robert B. Bacastow1, Martin Wahlen1, Timothy P. Whorf1, Martin Heimann2, and Harro A. Meijer3 Sio Reference No. 01-07 (Revised From Sio Reference No. 00-22) June 2001 http://cdrg.ucsd.edu/pdf_files/gaim_1.pdf.
23.
BeckE., Evidence of variability of atmospheric CO2 concentration during 20th century, 2008, presented at the Geo-ecological Seminar, University of Bayreuth (Germany) 17th July 2008. http://www.geo.uni-bayreuth.de/kolloq/
NeftelA.MoorE.OeschgerH., and StaufferB. (1985, 2 May). Evidence from polar ice cores for the increase in atmospheric co2 in the past two centuries. Nature315, 45–47. http://cdiac.ornl.gov/trends/co2/siple.htm.
28.
ChristnerBrent C.Recovery and Identification of Viable Bacteria Immured in Glacial Ice Icarus144, 479–485 (2000)