1.  John C. Hotton. 1931.  The Original Lists of Persons of Quality.  G.A. Baker & Co., Inc., NY.  On p. 35:

8 Aprilis 1635.  Theis pties herevnder mencioned are to be transported to New England: imbarqued in the Elizabeth of London Wm Stagg Mr. (master) bound thither: they have taken the oath of Allegeance & Supremacie p Cert: from the pish of St. Alphage Cropplegate the Minister there, Tanners: Wm Holdred, 25; Roger Preston, 21; Daniell Brodley, 20.  That theis 3 pties are no Subsedie men: wee whose names herevnto are written belonging to Blackwell Hall, do averr they are none.  Robte Farrands.  Thomas Smith.

2.  Peter Wilson Coldham.  1988/98.  The Complete Book of Emigrants, Volume 1, 1607-1660.  Genealogical Publ. Co., Baltimore, MD (Broderbund CD-350), citing E157/20, Public Record Office (Chancery Lane, London WC2A 1 LR, England):

6-17 April 1635.  Passengers embarked in the Elizabeth, Mr. William Stagg, bound from London to New England...  William Holdred 25, Roger Preston 21, Daniell Brodley 20 and Isack Studman, tanners of St. Alphage Cripplegate...

3.   Charles Henry Preston.  1931.  Descendants of Roger Preston of Ipswich and Salem Village.  The Essex Institute, Salem, MA (online at GenealogyLibrary.com, as of 21 Aug 2000).

4.  Daniel C. Preston. 1913.  The Preston Genealogy:  Orange County Branch and Life Sketch of the Compiler.  Self-published (online at GenealogyLibrary.com).

5.  LDS.  Ancestral File (online).  The AF wrongly equates Roger PRESTON of Ipswich with Roger PRESTON, Jr., of Up-Ottery, Devonshire.  They are not the same person.  Please see discussion of the Identity of Roger Preston.

7.  William Bowker Preston.  1900.  The Preston Genealogy: Tracing the History of the Family from about 1040, A.D., in Great Britain, in the New England States, and in Virginia, to the Present Time.  Self-published (online at GenealogyLibrary.com).  The author appears to equate Roger PRESTON of Ipswich with Roger PRESTON, Jr., of Up-Ottery, Devonshire. Please see pedigree chart of Leolphus de Preston and the discussion of the Identity of Roger Preston. 

8.  The Preston/Lindsey Trail (1995, self-published) by Rosaline Preston (17369 Road 6 SE, Warden, WA 98857) and Carol Huber  (10508-A Witter Springs Rd., Witter Springs, CA 95493).