REFERENCES
- Pavlov , P. and Lozanov , E. 1987 . Yearbook Higher Inst. Chem. Technol. Sofia , 28 ( No. 4 ) to be published (Part I of series)
- Pavlov , P. and Lozanov , E. 1987 . Yearbook Higher Inst. Chem. Technol. Sofia , 28 ( No. 4 ) to be published (Part II of series)
- Pavlov , P. and Lozanov , E. 1987 . Yearbook Higher Inst. Chem. Technol. Sofia , 28 ( No. 4 ) to be published (Part III of series)
- Pavlov , P. and Lozanov , E. 1987 . Yearbook Higher Inst. Chem. Technol. Sofia , 28 ( No. 4 ) to be published (Part IV of series)
- Auth. 1978 . cert., Bulgaria, No. 40 653(