2,5-Bis(secondary amino) oxa- and thiadiazole photographic devel
2,5-Dicarbonylaminophenol dye-forming couplers
2-Equivalent acylacetamide yellow forming couplers with 2,6-diox
2-Substituted benzimidazoles in multicolor diffusion transfer
2-Thiouracil in heat-developable light-sensitive materials