article by Philip T. Hayes & George C. assisted by Cone published 1975 in Geological Survey Professional Paper

scholarly article by Philip T. Hayes published in January 1982

scholarly article

scientific article published in 1970

Conference paper

scholarly article published 1965

scientific article published in 1979

article by Philip T. Hayes & Josete Caetana Dani Sanchez published 1979 in Coal Investigations

article by Josete Caetana Dani Sanchez & Philip T. Hayes published 1979 in Coal Investigations

article by J.D. Sanchez et al published 1977 in Open-File Report

article by J.D. Sanchez et al published 1978 in Geologic Quadrangle

article by Philip T. Hayes et al published 1977 in Open-File Report

article by Philip T. Hayes et al published 1977 in Geologic Quadrangle

scholarly article by Harley Barnes published in January 1954

scholarly article by Philip T. Hayes published in January 1955

scholarly article by Philip T. Hayes published in January 1958

scholarly article by Philip T. Hayes published in January 1964

scientific article published in 1967

scientific article published in 1980

article by Philip T. Hayes et al published 1965 in U.S. Geological Survey Bulletin

article by Philip T. Hayes published 1967 in Open-File Report

scientific article published in 1970

scientific article published in 1967

scientific article published in 1965

article by E.R. Landis & Philip T. Hayes published 1973 in Open-File Report

scientific article published in 1977

scientific article published in 1977

scientific article published in 1975

article by Philip T. Hayes published 1972 in U.S. Geological Survey Bulletin

scholarly article

scientific article published in 1977