Malina, D., Sobczak-Kupiec, A., Tyliszczak, B., Bialik-Wąs, K., Wzorek, Z. (2012). 
	Propolis – beekeeping medicinal product. Technical Transactions, 2012, 115-123. doi: https://doi.org/10.4467/2353737XCT.14.123.1900