| Effect of air pollution on carbohydrate and nutrients concentrations in some deciduous tree species N Tzvetkova, D Kolarov Bulgarian Journal of Plant Physiology 22 (1-2), 53-63, 1996 | 62 | 1996 |
| Geographical distribution and epidemiological characteristics of visceral leishmaniasis in Bulgaria, 1988 to 2012 R Harizanov, I Rainova, N Tzvetkova, I Kaftandjiev, I Bikov, O Mikov Eurosurveillance 18 (29), 2013 | 38 | 2013 |
| A comparative study on plant morphology, gas exchange parameters, and antioxidant response of Ocimum basilicum L. and Origanum vulgare L. grown on industrially polluted soil I Stancheva, M Geneva, Y Markovska, N Tzvetkova, I Mitova, M Todorova, ... Turkish Journal of Biology 38 (1), 89-102, 2014 | 37 | 2014 |
| Photosynthetic response of maize plants against cadmium and paraquat impact G Chaneva, P Parvanova, N Tzvetkova, A Uzunova Water, air, and soil pollution 208, 287-293, 2010 | 34 | 2010 |
| Chemical composition and biochemical changes in needles of Scots pine (Pinus sylvestris L.) stands at different stages of decline in Bulgaria N Tzvetkova, C Hadjiivanova Trees 20, 405-409, 2006 | 30 | 2006 |
| Bioaccumulation of heavy metals by the leaves of Robinia pseudoacacia as a bioindicator tree in industrial zones N Tzvetkova, K Petkova Journal of Environmental Biology 36 (1), 59, 2015 | 28 | 2015 |
| Photosynthetic responses of nitrate-fed and nitrogen-fixing soybeans to progressive water stress E Kirova, N Tzvetkova, I Vaseva, G Ignatov Journal of Plant Nutrition 31 (3), 445-458, 2008 | 25 | 2008 |
| Senescence progression in a single darkened cotyledon depends on the light status of the other cotyledon in Cucurbita pepo (zucchini) seedlings: potential … K Ananieva, ED Ananiev, S Doncheva, K Georgieva, N Tzvetkova, ... Physiologia Plantarum 134 (4), 609-623, 2008 | 24 | 2008 |
| Possibility for using of two Paulownia lines as a tool for remediation of heavy metal contaminated soil N Tzvetkova, K Miladinova, K Ivanova, T Georgieva, M Geneva, ... Journal of Environmental Biology 36 (1), 145, 2015 | 21 | 2015 |
| Parasitic diseases in Bulgaria in 2012 I Rainova, I Marinova, R Harizanov, D Jordanova, I Kaftandjiev, I Bikov, ... Probl Infect Parasit Dis 42 (1), 29-38, 2014 | 19 | 2014 |
| Changes in photosynthetic capacity and polypeptide patterns during natural senescence and rejuvenation of Cucurbita pepo L. (zucchini) cotyledons K Ananieva, ED Ananiev, K Mishev, K Georgieva, N Tzvetkova, ... Plant Growth Regulation 54, 23-29, 2008 | 17 | 2008 |
| Stomatal control on photosynthesis in drought-treated subalpine pine saplings S Anev, A Ivanova, N Tzvetkova, M Panayotov, S Yurukov Genetics and Plant Physiology 6 (1-2), 43-53, 2016 | 16 | 2016 |
| Characterization of the tolerance to excess manganese in four maize varieties Z Stoyanova, C Poschenrieder, N Tzvetkova, S Doncheva Soil Science and Plant Nutrition 55 (6), 747-753, 2009 | 14 | 2009 |
| Evaluation of response of lettuce (Lactuca sativa L.) to temperature and light stress NT Shaban, N Tzvetkova, R Cherkez, P Parvanova Acta agrobotanica 69 (2), 2016 | 13 | 2016 |
| Photosynthesis and growth response of two Paulownia hybrid lines to heavy metals Cd, Pb and Zn. K Miladinova, Y Markovska, N Tzvetkova, K Ivanova, M Geneva, ... | 13 | 2014 |
| Effect of soil salinity on morphology and gas exchange of two Paulownia hybrids K Ivanova, M Geneva, S Anev, T Georgieva, N Tzvetkova, I Stancheva, ... Agroforestry systems 93, 929-935, 2019 | 9 | 2019 |
| Photosynthesis and growth responses of five Paulownia lines to salt stress K Ivanova, N Tzvetkova, T Georgieva, Y Markovska Compt. Rend. Acad. Bulg. Sci 67, 1101-1106, 2014 | 8 | 2014 |
| Opportunistic parasitic diseases associated with HIV infection in Bulgaria R Kurdova, T Marinova, D Jordanova, M Ivanova, N Tzvetkova, I Rainova Proceedings of the IX European Multicolloquium of Parasitology 1009, 435-440, 2004 | 8 | 2004 |
| Soil contamination in forest and industrial regions of Bulgaria N Tzvetkova, L Malinova, M Doncheva, D Bezlova, K Petkova, ... Soil contamination–current consequences and further solutions, 127-153, 2016 | 7 | 2016 |
| Current status, surveillance and control of parasitic diseases in Bulgaria in 2011 I Rajnova, D Jordanova, R Harizanov, I Marinova, KI Bikov И, N Tzvetkova Inf. J NCPID 2, 4-10, 2012 | 7 | 2012 |
