Complex sentence: Nilsson recorded one more album, "Flash Harry", co-produced by Bruce Robb and Steve Cropper, which was released in the UK but not in the US However, Nilsson increasingly began referring to himself as a "retired musician".
Split into simpler sentences: Nilsson recorded one more album, "Flash Harry", co-produced by Bruce Robb and Steve Cropper, which was released in the UK but not in the US. From this point onward, Nilsson increasingly began referring to himself as a "retired musician".