“Aqueous solution of poly (hexamethylene guanidine hydrochloride) and poly (diethylenamine guanidine hydrochloride) as studied with acid-base indicators”, Khark. Univ. Bull. Chem. Ser., no. 33, pp. 65–76, Dec. 2019, doi: 10.26565/2220-637X-2019-33-05.