apollo. (2026). GISP2 and GISP2H nitrate and ammonium around 1908 (as used by Melott et al. 2010) (Version 1.0) [Data set]. Mysteries Department. https://mysteriesdept.com/datasets/DAT0D4ECSDE2S9F/gisp2-and-gisp2h-nitrate-and-ammonium-around-1908-as-used-by