Dahl, P., & Frei, R. (1998). Step-leach Pb-Pb dating of inclusion-bearing garnet and staurolite, with implications for Early Proterozoic tectonism in the Black Hills collisional orogen, South Dakota, United States. Geology. https://doi.org/10.1130/0091-7613(1998)026<0111:SLPPDO>2.3.CO;2
Dahl, Peter, and Robert Frei. 1998. “Step-Leach Pb-Pb Dating of Inclusion-Bearing Garnet and Staurolite, With Implications for Early Proterozoic Tectonism in the Black Hills Collisional Orogen, South Dakota, United States”. Geology. https://doi.org/10.1130/0091-7613(1998)026<0111:SLPPDO>2.3.CO;2.
Dahl, P., and R. Frei. Step-Leach Pb-Pb Dating of Inclusion-Bearing Garnet and Staurolite, With Implications for Early Proterozoic Tectonism in the Black Hills Collisional Orogen, South Dakota, United States. Geology, 1 Feb. 1998, doi:10.1130/0091-7613(1998)026<0111:SLPPDO>2.3.CO;2.