81. Bedrock geologic map of the Aitkin 30 x 60 minute quadrangle, east-central Minnesota, M-99, Plate 2
1999. Boerboom, Terrence J., Severson, Mark J., and Southwick, David L. Data base, Aitkin quadrangle showing drill holes, outcrops and other data used to make interpretations of bedrock geology for map M-99, scale 1:100... Minnesota Geological Survey.