The Puppet Masters
Robert A. Heinlein
Mechanicum
Graham McNeill
The Horus Heresy - Black Library recommended reading order (9)
Totality's End
Timothy Ellis
Star Well
Alexei Panshin
Anthony Villiers (1)
Beyond the Gap
Harry Turtledove
Opening of the World (1)
The Breath of God
Opening of the World (2)