3,3'-(1,4-Phenylenedimethylidene)bis(7,7-dimethyl-2-oxobicyclo(2.- 2.1)heptane-1-methanesulfonic acid 3,3'-(1,4-Phenylenedimethylidyne)bis(7,7-dimethyl-2-oxo-bicyclo(2.2.1)heptane-1-methanesulfonic acid 90457-82-2 Bicyclo (2.2.1) heptane-1-methanesulfonic acid, 3,3'-(1,4-phenylenedimethylidene) bis(7,7-dimethyl-2-oxo- Terephthalylidene dicamphor sulfonic acid