References
- 1989 . “Bulgarian State Standards on the Environment Pollution” , 2 volumes , Sofia : Standartizatsia . (in Bulgarian)
- 1994 . “Bulgarian State Standard. Regulation no. 2 of the Ministry of Health and Ministry of the Environment” , State Newspaper no. 43 (in Bulgarian)
- Garcia‐Delgado , R. , Garcia‐Herruzo , F. , Rodriguez‐Marroto , J. , Gomez‐Lahoz , C. and Castellon , C . 1996 . J. Environ. Sci. Health, Part A , A31 : 2087 – 2097 .
- Howard , J. and Sova , J. 1993 . J. Soil Contam. , 2 : 361 – 378 .
- Ignatenko , N. 1992 . “Ekol. ‐ Geochim. Anal. Teknol. Zagryaz.” , Edited by: Golovin , A. and Sorokina , E. 22 – 28 . Moskow : Inst. Mineral Geokhim. Kristalokhim. Red. Elem. . (in Russ.)
- 1993 . “Ministry of the Environment, Annual on the Environmental Quality in Bulgaria” , Sofia : Ministry of the Environment . (in Bulgarian)
- Nemeth , T. , Molnar , E. , Csillag , J. , Bujtas , K. , Lukas , A. , Partay , G. , Feher , J. and Van Genuchten , M . 1993 . Wat. Sci. Techn. , 28 : 389 – 398 .
- Panayotova , M. and Zabchev , A. “Chemistry, Energy and the Environment” . Proc. 3rd Workshop on Chemistry, Energy and the Environment . May 25–28 1997 , Estoril, Portugal. Edited by: Sequeira , C. A. C. and Moffat , J. B. pp. 417 – 425 . Cambridge : The Royal Society of Chemistry .
- Swamy , K. , Veerabhadra , T. and Cokesh , K. 1993 . Indian J. Environ. Health , 35 : 205 – 209 .
- Totev , T. , Gribachov , P. , Nechev , H. and Artinova , N. 1991 . “Guidebook for Exercises on Soil Science” Zemizdat, Sofia (in Bulgarian)
- Ure , A. 1996 . The Sci. of Tot. Environ. , 178 : 3 – 12 .