Stöffler, D.; Ryder, G. Stratigraphy and Isotope Ages of Lunar Geologic Units: Chronological Standard for the Inner Solar System. Space Science Reviews. 2001, 96 (1-4). Bibcode:2001SSRv...96....9S. doi:10.1023/A:1011937020193.
Stöffler, D.; Ryder, G. Stratigraphy and Isotope Ages of Lunar Geologic Units: Chronological Standard for the Inner Solar System. Space Science Reviews. 2001, 96 (1-4). Bibcode:2001SSRv...96....9S. doi:10.1023/A:1011937020193.