Chemistry of 1,3-bifunctional compounds 3. Aminoalkyl esters of xanthene-9-carboxylic acid 2. : Cholinolytic and bronchodilator activity of quaternary salts of new diaminoalkyl-xanthene-9-carboxylates - Felföldi K.; Laszlavik M.; Bartók Mihály; Kárpáti E. (1980)