TY - RPRT TI - Transcontinental geophysical survey (35°-39° N) magnetic map from 87° to 100° W longitude AU - Isidore Zietz AU - J.R. Kirby PY - 1968 DO - 10.3133/i534a UR - https://pubs.usgs.gov/publication/i534A ID - i534A ER -