1. Information company Tracerco,
https://www.tracerco.com/pdfs-uploaded/Tracerco%20Profiler_Brochure_USA.pdf
.
2. V. I. Osipov, Determination of Density and Moisture Content of Soils from Scattering of Gamma-rays and Neutrons [in Russian], Izd. MGU, Moscow (1968), p. 157.
3. Information company Troxler,
www.troxlerlabs.com/Portals/0/Troxler%20Documents/Marketing%20Documents/3430_3440%20Brochures/3430-40%20Brochure%20102015.pdf
.
4. Valery Dmitrenko and Nobuyulci Hasebe, Modern Status of High-Pressure Xenon Gamma-ray Spectrometers and their Applications,
https://indico.cern.ch/event/573069/sessions/230057/attachments/1439112/2214469/XeSAT2017_report_VVD-NH.pdf
.
5. C. J. Borkowski and M. K. Kopp, Rev. Sci. Instrum., 39, 1515 (1968).