TY - RPRT TI - Action spectrum for paling (decrease in refractive index) of ultraviolet-irradiated chromosome segments. AU - R E ZIRKLE AU - R B URETZ PY - 1963 DO - 10.1073/pnas.49.1.45 UR - https://pubmed.ncbi.nlm.nih.gov/14003787/ ID - 14003787 ER -