E.E. 'Doc' Smith SF Gateway Omnibus : The Skylark of Space, Skylark Three, Skylark of Valeron, Skylark Duquesne (Paperback) - The SF Gateway Omnibus 13
Barrington Bayley SF Gateway Omnibus : The Soul of the Robot, The Knights of the Limits, The Fall of Chronopolis (Paperback) - The SF Gateway Omnibus 28