REFERENCES
- Kenderov L. and Apostolov A. (2008) Natura Montenegrina, 7(2), 145–167.
- Kenderov L., Yaneva I. and Pavlova M. (2008) Acta zoologica bulgarica, Suppl.2. 255–268.
- Margalev R. (1958) Information theory in ecology. General Systems, 3, 36–71.
- MEW (1986) Regulation 7. Indices and standards for determination of the admissible pollution rate of the different categories running surface waters. OJ. 96/1986
- Pantle R. and Buck H. (1955) Die biologische Uberwachung der Gewasser und die Darstellung der Ergebnisse.- Gas und Wasserfach, 96, 604.
- Parvanov D., Topalova Y. and Kenderov L. (2008) Ecological engineering and environmental protection, 4, 4–11.
- Parvanov D., Topalova Y. and Yaneva I. (2007) Ecological engineering and Environmental protection, 6(1), 21–30.
- Pielou E. (1966) Journal of Theorethical Biology, 10(6), 370–383.
- Russev B. (ed.). (1994) Limnology of Bulgarian Danube tributaries. Book Tiger, 255 pp. (in Bulgarian).
- Shannon S. and Weaver, W. (1963) The mathematical theory of communication. Urbana University Illinois Press, 117 pp.
- Simpson E. (1949) Nature, 163, 688.
- Vassilev Y. and Uzunov Y. (2004) Acta Zoologica Bulgarica, 56(1), 93–103.