- Geological Survey (U.S.), 1968, Aeromagnetic map of the Kabetogama Lake-Grassy Lake area, St. Louis County, Minnesota: Geophysical Investigation Map 616, 1 map.,
- Geological Survey (U.S.), 1968, Aeromagnetic map of the Palmer quadrangle, Hampden, Hampshire, and Worcester Counties, Massachusetts: Geophysical Investigation Map 617, 1 map.,
- Geological Survey (U.S.), 1968, Aeromagnetic map of the Springfield North quadrangle, Hampden and Hampshire Counties, Massachusetts: Geophysical Investigation Map 618, 1 map.,
- Geological Survey (U.S.), 1968, Aeromagnetic map of the Ludlow quadrangle, Hampden and Hampshire Counties, Massachusetts: Geophysical Investigation Map 619, 1 map.,
- Geological Survey (U.S.), 1968, Aeromagnetic map of the Warren quadrangle, Worcester, Hampden, and Hampshire Counties, Massachusetts: Geophysical Investigation Map 620, 1 map.,
- Geological Survey (U.S.), 1968, Aeromagnetic map of the East Brookfield quadrangle, Worcester County, Massachusetts: Geophysical Investigation Map 621, 1 map.,
- Geological Survey (U.S.), 1968, Aeromagnetic map of the Mount Tom quadrangle and part of the Woronoco quadrangle, Hampden and Hampshire Counties, Massachusetts: Geophysical Investigation Map 622, 1 map.,
- Geological Survey (U.S.), 1968, Aeromagnetic map of the Worcester South quadrangle, Worcester County, Massachusetts: Geophysical Investigation Map 623, 1 map.,
- Geological Survey (U.S.), 1968, Aeromagnetic map of the Leicester quadrangle, Worcester County, Massachusetts: Geophysical Investigation Map 624, 1 map.,
- Geological Survey (U.S.), 1968, Aeromagnetic map of the Chester quadrangle and parts of the Beckett and Blandford quadrangles, Berkshire, Hampden, and Hampshire Counties, Massachusetts: Geophysical Investigation Map 625, 1 map.,
- Geological Survey (U.S.), 1968, Aeromagnetic map of the Goshen quadrangle and part of the Ashfield quadrangle, Franklin and Hampshire Counties, Massachusetts: Geophysical Investigation Map 626, 1 map ;61 x 43 cm.,
- Geological Survey (U.S.), 1968, Aeromagnetic map of the Worthington quadrangle and parts of the Plainfield and Peru quadrangles, Berkshire and Hampshire Counties, Massachusetts: Geophysical Investigation Map 627, 1 map.,
- Geological Survey (U.S.), 1968, Aeromagnetic map of the Westhampton quadrangle and part of the Woronoco quadrangle, Hampshire County, Massachusetts: Geophysical Investigation Map 628, 1 map.,
- Geological Survey (U.S.), 1968, Aeromagnetic map of the Hampden quadrangle, Hampden County, Massachusetts, and Tolland County, Connecticut: Geophysical Investigation Map 629, 1 map.,
- Geological Survey (U.S.), 1968, Aeromagnetic map of the Monson quadrangle, Hampden County, Massachusetts, and Tolland County, Connecticut: Geophysical Investigation Map 630, 1 map.,
- Geological Survey (U.S.), 1968, Aeromagnetic map of the Southbridge quadrangle, Worcester County, Massachusetts, and Windham and Tolland Counties, Connecticut: Geophysical Investigation Map 631, 1 map ;58 x 43 cm.,
- Geological Survey (U.S.), 1968, Aeromagnetic map of the Springfield South quadrangle, Hampden County, Massachusetts, and Hartford and Tolland Counties, Connecticut: Geophysical Investigation Map 632, 1 map ;58 x 43 cm.,
- Geological Survey (U.S.), 1968, Aeromagnetic map of the Wales quadrangle, Hampden and Worcester Counties, Massachusetts, and Tolland County, Connecticut: Geophysical Investigation Map 633, 1 map.,
- Geological Survey (U.S.), 1968, Aeromagnetic map of the Webster quadrangle, Worcester County, Massachusetts, and Windham County, Connecticut: Geophysical Investigation Map 634, 1 map ;57 x 43 cm., on sheet 81 x 57 cm.,
- Geological Survey (U.S.), 1968, Aeromagnetic map of the West Springfield quadrangle and part of the Southwick quadrangle, Hampden County, Massachusetts, and Hartford County, Connecticut: Geophysical Investigation Map 635, 1 map.,
- Geological Survey (U.S.), 1968, Aeromagnetic map of central Pine County, Minnesota, and adjacent parts of Wisconsin: Geophysical Investigation Map 636, 1 map.,
- Geological Survey (U.S.), 1968, Aeromagnetic map of the Hot Creek Range region, south-central Nevada: Geophysical Investigation Map 637, 1 map.,
- Peterson, D. L., 1968, Bouguer gravity map of parts of Maricopa, Pima, Pinal, and Yuma Counties, Arizona: Geophysical Investigation Map 615, 1 map.,
- Peterson, D. L.; Popenoe, Peter; Gaca, J. R.; Karig, D. E., 1968, Gravity map of the Trinidad quadrangle, Colorado a contribution to the Upper Mantle Project: Geophysical Investigation Map 638, 1 map ;on sheet 56 x 85 cm.,
