Seppelin, T.O. External Organizations; Publikationen aller ICGEM-unterstützten Projekte, Deutsches GeoForschungsZentrum;
,
Seppelin, T. (1974): The Department of Defense World Geodetic System 1972 - The Department of Defense World Geodetic System 1972, International Symposium on Problems Related to the Redefinition of North American Geodetic Networks (Fredrickton, New Brunswick, Canada).