Photochromic properties of 1′,3′,3′ -trimethyl-6- nitrospiro[2H-1-benzopyran-2,2′-indoline] doped in PMMA and epoxy resin thin films
Photochromic properties of 1′,3′,3′ -trimethyl-6- nitrospiro[2H-1-benzopyran-2,2′-indoline] doped in PMMA and epoxy resin thin films