1. Gamma radiation absorption coefficients of air in the energy range 0.01 to 100MeV;Allison;J. Appl. Phys.,1958
2. Berger, M.J., Hubbell, J.H., Seltzer, S.M., Chang, J., Coursey, J.S., Sukumar, R., Zucker, D.S., Olsen, K., 2010. Xcom: Photon cross section database, Tech. Rep. 3597, National Institute of Standards and Technology, Gaithersburg, MD.
3. Briesmeister, J.F., 1993. Mcnp a general purpose Monte Carlo N-Particle transport code, Version 4A, Tech. Rep. LA-12625, Los Alamos National Laboratory report.
4. Applied Gamma-ray Spectrometry;Crouthamel,1970
5. Local densitometry of wood by gamma back-scattering;Divos;Holz als Roh Werkstoff,1996