Duncan J. McGregor books & textbook
Guide to Some Minerals and Rocks in Indiana, Geological Survey, circular No.4
Seymour S. Greenberg Wayne M. Bundy Duncan J. McGregor
Indiana Dept of Conservation /1958-01-01 Paperback / 60 Pages
South Dakota's Rock History
Bruno C. Petsch and Duncan J. McGregor
South Dakota Geological Survey /2000T Staple Bound / 39 Pages
Minerals and rocks of South Dakota (Educational series, 5)
Bruno Carl Petsch Duncan J. McGregor
Science Center, University of South Dakota /1973-01-01 Paperback
