The Eclipse of Dawn (1971) A Trace of Dreams (1972) Beyond the Resurrection (1973) Inheritors of the Earth (1974) (with Poul Anderson) All Times Possible (1974) Serving in Time also known as Laser Books No. 6: Serving in Time (Laser Books, 1975, ISBN 0-373-72006-8) Falling Toward Forever also known as Laser Books No. 10.
The Eclipse of Dawn (1971) A Trace of Dreams (1972) Beyond the resurrection (1973) Inheritors of the Earth (1974) (med Poul Anderson) All Times Possible (1974) Serving in Time även som Laser Books No. 6: Serving in Time (Laser Books, 1975, ISBN 0-373-72006-8) Falling Toward Forever även som Laser Books No. 10.