Complex sentence: This was the first novelisation commissioned by Target following the successful republishing of three books originally published in the mid- 1960s; the Target Books novelisation series would run for the next twenty years and see all but a half-dozen "Doctor Who" serials adapted.
Split into simpler sentences: This was the first novelisation commissioned by Target following the successful republishing of three books originally published in the mid- 1960s. The Target Books novelisation series would run for the next twenty years and see all but six "Doctor Who" serials adapted.