1. Olmstead AL, Rhode PW (2008) Creating abundance: biological innovation and American Agricultural Development. Cambridge University Press, New York
2. Alexandrov V, Dubuisson B, Moisselin J-M, Koleva E (2006) A case study on utilization of precipitation indices in Bulgaria. In: Proceedings of the international conference on water observation and information system for decision support (BALWOIS), Ohrid, Macedonia, 23–26 May 2006, (CD), 18 pp
3. Bachvarova S, Dzhoreva M, Hristozova J, Senyov A (2008) Climatic anomalies and their impact on agricultural production in Bulgaria in 2007 – materials from the work of the National Commission for independent monitoring of the impact of adverse weather events agriculture. MAF, NCAS; NKNM, Sofia, 167 pp. ISBN-978-954-8045-10-0. (in Bulgarian)
4. Croitoru A-E, Chiotoroiu B-C, Todorova V, Torica V (2013) Changes in precipitation extremes on the Black sea Western coast. Glob Planet Chang 102:10–19
5. Rosenzweig C, Hillel D (1998) Climate change and the global harvest: potential impacts of the greenhouse effect on agriculture. Oxford University Press, Oxford