Complex sentence: Holley began his professional career at the University of Houston and worked there for nine years before moving to Chapel Hill, North Carolina in 1972 to assume the position of dean and professor in the School of Information and Library Science.
Split into simpler sentences: Holley began his professional career at the University of Houston and worked there for nine years. In 1972 he moved to Chapel Hill, North Carolina, where he accepted the position of dean and professor in the School of Information and Library Science.