Havel, J Spectrophotometric determination of rare earth elements by flow injection analysis based on their reaction with xylenol orange and cetylpyridinium bromide. [electronic resource] - Talanta Aug 1994 - 1251-4 p. digital Publication Type: Journal Article ISSN: 0039-9140 Standard No.: 10.1016/0039-9140(93)e0044-e doi