1. Achilea O, Soffer Y, Raber D et al (2002) Bonus-NPK – highly concentrated, enriched potassium nitrate, an optimal booster for yield and quality of citrus fruits. Acta Hort 594:461–466
2. Barczak B, Cwojdziński W (1998) Content of macroelements in cucumber fruits sprayed with pesticides and the lupine extract. Sci Papers Agric Univ Poznann 27:11–18 (in Polish with English abstract)
3. Barczak B, Majcherczak E, Kozera W (2007) Effect of lupine extract and nitrogen fertilization on yield quality of celeriac. Veg Crop Res Bull 66:59–68. doi: 10.2478/v10032-007-0008-6
4. Basak A, Mikos-Bielak M (2008) The use of some biostimulators on apple and pear trees. In: Sadowski A (ed) Biostimulators in modern agriculture - fruit crops. Editorial House Wiesn Jutra, Warsaw
5. Beck SL, Dunlop RW, Fossey A (2003) Stomatal length and frequency as a measure of ploidy level in black wattle, Acacia mearnsii (de Wild). Bot J Linn Soc 141(2):177–181. doi: 10.1046/j.1095-8339.2003.00132.x