[1] Tarendash, A.S., Let's review: chemistry, the physical setting (3rd ed.). Barron's Educational Series, 2001( ISBN 978-0-7641-1664-3): p. p. 44.
 
 [2] Sloss, L.L., Nitrogen Oxides Control Technology Fact Book. William Andrew,1992. (ISBN 978-0-8155-1294-3): p.p. 6. 
[3] Methane and Nitrous Oxide Emissions from Natural Sources. US Environmental Protection Agency 2010(Report EPA 430-R-10-001).
 
[4] K. L. Denman, G. Brasseur, et al.(2007), "Couplings Between Changes in the Climate System and Biogeochemistry". In Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Cambridge University Press.
[5]  IPCC. 2013. Climate change: the physical basis (WG I, full report). p. 512.
[6] Molodovskaya, M.; Singurindy, O.; Richards, B. K.; Warland, J. S.; Johnson, M.; Öberg, G.; Steenhuis, T. S. (2012). "Temporal variability of nitrous oxide from fertilized croplands: hot moment analysis". Soil Science Society of America Journal76 (5): 1728–1740. 
[7]  Overview of Greenhouse Gases – Nitrous Oxide" . US EPA. 2014-06-10. Page 164 (document header listing). Retrieved 19 March 2014.
[8] US Environmental Protection Agency, "Climate Change Indicators: Atmospheric Concentrations of Greenhouse Gases" Web document, accessed on 2017-02-14.
[9] 4.1.1 Sources of Greenhouse Gases"IPCC TAR WG1 2001. Archived from the original on 29 October 2012. Retrieved 21 September 2012.
[10] Abood, Z. M and Al-Taai, O. T(2018), Study  of Absorbance and Emissivity Solar Radiation by Clouds, Aerosols and some Atmospheric gases. Journal of  Applied and Advanced,3(5):p.128-134.
[11] Reanalysis at ECMWF, "The European Center for Medium –Range Weather Forecasts" .Available(http://ecmwf.int/research/era/do/get/Reanalysis_ECMWF).[Accessed:06-Oct-2018].
 
[12] Rashed, S .M and Al-Taai, O. T(2017),  Analysis study of Meteorological Parameters and their Relationship with some Concentration of Tropospheric Gases over Erbil City.ZANCO journal of pure and Applied Sciences,29(S4):P.234-248.
[13] Sigmaplot .Scientific Data Analysis and Graphing Software [Web] ; Available: www.sigmaplot.co.uk/products/sigmaplot/sigmaplot-details.php.   [Accessed 05/02/2019].