Complex sentence: Overmans joined the Bundeswehr in 1972, and studied economics at the Bundeswehr University Munich from 1974 to 1977 and completed his Ph.D in 1982--1986 at the Bundeswehr University Hamburg.
Split into simpler sentences: Overmans joined the Bundeswehr in 1972, and studied economics at the Bundeswehr University Munich from 1974 to 1977. He completed his Ph.D in 1982--1986 at the Bundeswehr University Hamburg.