1. AARKROG, A.; BOETTER-JENSEN, L.; CHEN QING JIANG; DAHLGAARD, H.; HANSEN, H.; LAURIDSEN, B.; NIELSEN, S. P.; STRANDBERG, M.; SOEGAARD-HANSEN, J. (Risoe National Lab. Denmark)); HOLM, E. (Risoe National Lab. Roskilde (Denmark) Health Physics Dept.): Environmental radioactivity in Denmark 1990 and 1991. (English). Riso-R-621 (EN). ISBN 87-550-1802-5. Dec 1992. 174 p. MF available from Risoe Library, DK-4000 Roskilde, Denmark. (RN 24:037677).
2. AARKROG, A.; DAL'GAARDT, G.; KARAVAEVA, E. N. (AN SSSR, Sverdlovsk (Russian Federation). Inst. Ehkologii Rastenij i Zhivotnykh): On the content of long-living radioisotopes in soils and trees of zone of the South Urals nuclear accident. (Russian). O soderzhanii dolgozhivushchikh radionuklidov v pochvakh i drevesnykh rasteniyakh zony yadernoj avarii na Yuzhnom Urale.Ehkologiya. ISSN 0367-0597. EKIAAK. (Jul–Aug 1992). (no. 4) p. 50–55. (RN 25:017726).
3. ABDULLA, I. K. (Salahaddin Univ., Sulaimaniya (Iraq). Coll. of Science) The study of radioactivity of different geological layers of Al-Khazir area. Thesis (M.Sc). (Arabic). Iraq. 1991. 145 p. Available from Information Center, Iraqi Atomic Energy Commission, Tuwaitha-Baghdad, P.O. Box 765, Iraq. (RN 25:025066).
4. STI/PUB-908;M. Abe,1993
5. ANON (Bundesamt für Gesundheitswesen (BAG), Bern (Switzerland)): Environmental radioactivity and radiation doses in Switzerland 1992. (German, English, French, Italian). Umwelt-radioaktivität und Strahlendosen in der Schweiz 1992. ISBN 3-905235-09-9-Bern (Switzerland). Bundesamt für Gesundheitswesen. Abteilung Strahlenschutz. Jul 1993. [240 p.]. (RN 25:018020).