6. Hummel M., Findlay S. 2006. Effects of water chestnut (Trapa natans) beds on qater chemistry in the tidal freshwater Hudson River. -- Hydrobiologia. 559(1): 169-181. DOI: 10.1007/s10750-005-9201-0
7. Ishbirdin A.R., Ishmuratova M.M., Zhirnova T.V. 2005. Life strategies of the coenopopu- lation Cephalanthera rubra (L.) Rich. On the territory of the Bashkir State Reserve. -- Vest- nik of Lobachevsky University of Nizhni Novgorod. Biology Ser. 1: 85-98. (In Russ.).
8. Kadono Y., Schneider E.L. 1986. Floral biology of Trapa natans var. japonica. -- The Botanical Magazine Tokyo. 99(4): 435-439. DOI: 10.1007/bf02488722
9. Kashin A.S., Parkhomenko A.S., Bogoslov A.V., Shilova I.V., Kulikova L.V., Grebenyuk L.V., Petrova N.A. 2019. The results of the reintroduction of Trapa natans L. in the river. Khoper in the Saratov region. -- In: Scientific works of the Khvalynsky National Park. 11: 67-72. (In Russ.).
10. Kashin A.S., Petrova N.A., Shilova I.V. 2016 b. Features of the ecological strategy of Tulipa gesneriana L. (Liliaceae, Liliopsida). -- Povolzhskiy J. of Ecology. 2: 209-221. DOI: 10.18500/1684-7318-2016-2-209-22 (In Russ.).
11. Kashin A.S., Petrova N.A., Shilova I.V., Kulikova L.V. 2016 a. Prospects for the reintroduction of Trapa natans (Trapaceae) in the Saratov region. -- Rastitelnye Resursy. 4: 47-62. (In Russ.).
12. Kurihara M., Ikusima I. 1991. The ecology of the seed in Trapa natans var. japonica in a eutrophic lake. --Vegetatio. Vol. 97. P. 117-124.
13. Leskov A.P. 2010. Ecology and biology Trapa natans L. (Eastern Transbaikalia). -- Uchenye Zapiski Zabaikalskogo Gosudarstvennogo Universiteta. 1 (30): 140-146. (In Russ.).
14. Lim T.K. 2013. Trapa natans L. -- In: Edible Medicinal And Non-Medicinal Plants. Vol. 5. Springer. P. 195-201.
15. Markov M.V. 2012. Population biology of plants. Moscow. 387 p. (In Russ.).
16. Nobis M., Klichowska E., Nowak A., Gudkova P.D., Rola K. 2016. Multivariate morphometric analysis of the Stipa turkestanica group (Poaceae: Stipa sect. Stipa). -- Pl. Syst. Evol. 302(2): 137-153. DOI: 10.1007/s00606-015-1243-9
17. Parkhomenko V.M., Kashin A.S. 2011. State of Hypericum perforatum L. cenopopula- tions in Saratov region: variability of morphometric characters and survival strategy. -- Rastitelnye Resursy. 47(4): 1-18. (In Russ.).
18. Pfingsten, I.A., Cao L., Berent. L. 2020. Trapa natans L.: U.S. Geological Survey, Nonin- digenous Aquatic Species Database, Gainesville, FL. https://nas.er.usgs.gov/queries/FactSheet.aspx?SpeciesID=263 (Accessed 27.05.2020).
19. Podani J. 2000. Introduction to the exploration of multivariate biological data. Leiden. 407 p.
20. Rai U.N., Sinha S. 2001. Distribution of metals in aquatic edible plants: Trapa natans (Roxb.) Makino and Ipomoea aquatica Forsk. -- Environmental Monitoring and Assessment. 70(3): 241-252. DOI: 10.1023/a:1010727325662
21. Rebrova O.Yu. 2006. Statistical Analysis of Medical Data. Application of the STATISTICA application package. Moscow. 312 p. (In Russ.)
22. Rostova N.S. 2002. Correlations: structure and variability. Saint-Petersburg. 308 p. (In Russ.).
23. Shilova I.V., Bogoslov A.V., Kashin A.S., Kritskaya T.A., Parkhomenko A.S., Petrova N.A. 2019. Morphometric characteristics and vitality structure of Delphinium pubiflorum cenopopulations. -- In: Materials of the All-Russian conference with international participation dedicated to the memory of R.E. Levina «Modern problems of morphology and reproductive biology of seed plants» (Ulyanovsk, April 17-19, 2019). Collection of scientific articles. Ulyanovsk: UlSPU. P. 121-128. (In Russ.)
24. Skliar Iu. L., Skliar V.H. 2017. Trapa natans L. s.l. growth features in Desna River basin. -- Ukrainian Journal of Ecology. 7(3): 239-245. DOI: 10.15421/2017_74
25. Sneath P.H.A., Sokal R.R. 1973. Numerical taxonomy. San Francisco. 573 p.
26. Tikhonova V.L., Belovodova N.N. 2002. Reintroduction of wild-growing herbaceous plants; state of the problem and prospects. -- Bulletin of the Central Botanical Garden. 183: 90-106. (In Russ.).
27. Torrecilla P., Acedo C., Marques I., Diaz-Perez A. J., Lopez-Rodriguez J. A., Mirones V., Sus A., Llamas F., Alonso A., Perez-Collazos E., Viruel J., Sahuquillo Sancho M. D., Komac B., Manso J. A., Segarra-Moragues J. G., Draper D., Villar L., Catalan P. 2013. Morphometric and molecular variation in concert: taxonomy and genetics of the reticulate Pyrenean and Iberian alpine spiny fescues (Festuca eskia complex Poaceae). -- Bot. J. Linn. Soc. 173(4): 676-706. DOI: 10.1111/boj.12103
28. Tzvelev N.N. 1964. About the way of distribution of the water nut Trapa L. in the past and its extinction in the historical time. -- Bot. Zhurn. 49(9): 1338-1340. (In Russ.).
29. Zhigacheva O.I. 2013. Consortium ties of water chestnut (Trapa natans L. s. l., Trapaceae) in the Volga basin. -- Izvestiya of Saratov University. Chemistry. Biology. Ecology. 13(2): 74-77. (In Russ.)
30. Zlobin Yu.A., Sklyar V.G., Klimenko A.A. 2013. Populations of rare plant species: theoretical foundations and research methods. Sumy. 439 p. (In Russ.).