1. N. Ahmad, M. S. Jaafar, M. Bakhash, M. Rahim. An overview on measurements of natural radioactivity in Malaysia. J. Radiat. Res. Appl. Sci. 8 (2015) 136-141.
2. A. Papadopoulos , G. Christofides, A. Koroneos, L. Papadopoulou, C. Papastefanou, S. Stoulos. Natural radioactivity and radiation index of the major plutonic bodies in Greece. J. Environ. Radioact. 124 (2013 ) 227-238.
3. Ministry of Energy, British Columbia, Common Rock Types, 2014.
4. T. Santawamaitre, D. Malain, H. A. Al-Sulaiti, M. Matthews, D. A. Bradley, P. H. Regan. Study of natural radioactivity in riverbank soils along the Chao Phraya river basin in Thailand. Nucl. Instrum. Methods Phys. Res. A. 652 (1) (2011) 920-924.
5. A. Abbady, N. K. Ahmed, A. M. El-arabi, R. Michel, A. H. El-kamel, A. G. E. Abbady. Estimation of radiation hazard indices from natural radioactivity some rocks. Nucl. Sci. Techniques 17 (2) (2006) 118–122.
6. A. M. El-Arabi, N. K. Ahmed, A. H. El-Kamel. Gamma spectroscopic analysis of powdered granite samples in some Eastern desert’s areas. Arab J. Nucl. Sci. Appl. 34 (2001) 245-255.
7. A. I. Abd El-mageed, A. H. El-Kamel, A. Abbady, S. Harb, A. M. M. Youssef, I. I. Saleh. Assessment of natural and anthropogenic radioactivity levels in rocks and soils in the environments of Juban town in Yemen. Radiat. Phys. Chem. 80 (6) (2011) 710-715.
8. C. Papastefanou. Measurement Of Naturally Occurring Radionuclides With Several Detectors: Advantages And Disadvantages. In: G. A. Aycik (eds) New Techniques for the Detection of Nuclear and Radioactive Agents. NATO Science for Peace and Security Series B: Physics and Biophysics. Springer, Dordrecht, 2009.
9. K. Dabayneh, L. Mashal, F. Hasan. Radioactivity concentration in soil samples in the southern part of the West Bank, Palestine. Radiat. Prot. Dos. 131 (2008) 265-271.
10. K. Thabayneh, M. Jazzar. Natural radioactivity levels and estimation of radiation exposure in environmental soil samples from Tulkarem Province –Palestine. Open J. Soil Sci. 2 (2012) 7-16.
11. E. Faweya, A. Babalola. Radiological safety assessment and occurrence of heavy metals in soil from designated waste dumpsites used for building and composting in Southwestern Nigeria. Arab J. Sci. Eng. 35 (2010) 220.
12. W. E. Meyerhof. Elements of Nuclear Physics. McGraw-Hill, New York,1967.
13. N. Huy, T. Luyen. Study on external exposure doses from terrestrial radioactivity in Southern Vietnam. Radiat. Prot. Dos. 118 (2005) 331–336.
14. H. Abdel-Ghany. Natural activities of 238 U, 232 Th and 40 K in manganese ore. Am. Env. Sci. 6 (2010) 90-94.
15. W. Alharbi, J. AlZahrani, A. Abbady. Assessment of radiation hazard indices from granite rocks of the South-Eastern Arabian Shield. Kingdom of Saudi Arabia. Austr. J. Basic Appl. Sci. 5 (2011) 672-682.
16. A. El-Shershaby, S. El-Bahi, N. Walley El-Din, K. Dabayneh. Assessment of natural and man-made radioactivity levels of the plant leaves samples as bio-indicators of pollution in Hebron districtPalestine. Arab J. Nucl. Sci. Appl. 39 (2006) 232-242.
17. I. Fatima, J. Zaidi, M. Arif, M. Daud, S. Ahmad, S. Tahir. Measurement of natural radioactivity and dose rate assessment of terrestrial gamma radiation in the soil of southern Punjab, Pakistan. Radiat. Prot. Dosim 128 (2008) 206–212.
18. UNSCEAR. Report to the General Assembly. New York, NY, USA: UNSCEAR, 1993.
19. R. Veiga, N. Sanches, R. M. Anjos, K. Macario, J. Bastos, M. Iguatemy, J. G. Aguiar, A. M. Santos, B. Mosquera, C. Carvalho, M. Baptista Filho, N. K. Umisedo. Measurement of natural radioactivity in Brazilian beach sands. Rad. Meas. 41 (2006) 189-196.
20. I. Shams, U. Mohamed, E. Reda. Gamma radioactivity measurements in Nile River sediment samples. Turkish J. Eng. Env. Sci. 37 (2013) 109-122.
21. N. Huy, T. Luyen. Study on external exposure doses from terrestrial radioactivity in Southern Vietnam. Radiat. Prot. Dos. 118 (2005) 331-336.
22. A. Mahur, R. Kumar, M. Mishra, S. Ali, R. Sonkawade, B. Singh, V. Bhardwaj, R. Prasad. Study of radon exhalation rate and natural radioactivity in soil samples collected from east Singhbhum Shear zone in Jaduguda U-Mines Area, Jharkhand, India and its radiological implications. Ind. J. Pure Appl. Phys. 48 (2010) 486-492.
23. J. Beretka, P. Mathew. Natural radioactivity in Australian building materials, industrial waste and by-products. Health Phys. 1 (1985) 87-95.
24. UNSCEAR. Report to the General Assembly. New York, NY, USA: UNSCEAR, 2000.
25. F. Al-Saleh, B. Al-Berzan. Measurements of natural radioactivity in some kinds of marble and granite used in Riyadh Region. J. Nucl. Rad. Phys. 2 (2007) 25-36.
26. V. Ramasamy, G. Suresh, V. Meenakshisundaram, V. Gajendran. Evaluation of natural radionuclide content in river sediments and excess lifetime cancer risk due to gamma radioactivity. Res. J. Env. Earth Sci. 1 (2009) 6-10.
27. H. Taskin, M. Karavus, P. Ay, A. Topuzoglu, S. Hindiroglu, G. Karahan. Radionuclide concentrations in soil and lifetime cancer risk due to the gamma radioactivity in Kirklareli, Turkey. J. Env. Radiat. 100 (2009) 49-53.
28. K. Thabayneh, M. Jazzar. Natural radioactivity levels and estimation of radiation exposure in environmental soilsamples from Tulkarem Province Palestine. Open J. Soil Sci. 2 (2012) 7-16.
29. UNSCEAR. Report to the General Assembly. NewYork, NY, USA: UNSCEAR, 2000.
30. UNSCEAR. Report to the General Assembly. NewYork, NY, USA: UNSCEAR, 1993.
31. European Commission, Directorate-General for Environment, Radiological protection principles concerning the natural radioactivity of building materials, Publications Office, 2000.