A good outline of the arguments for the unity of Isaiah:
Isaiah wrote Isaiah
An online article by J. Barton Payne:
http://www.biblicalstudies.org.uk/pd...aiah_payne.pdf
—J.A. Alexander, Prophecies of Isaiah (1847)
—F. Delitzsch, “Isaiah,” Imperial Bible Dictionary, III, 158-171 (1886)
—G. L. Robinson, “Isaiah,” ISBE, III, 1495-1508 (1929)
—O.T. Allis, The Unity of Isaiah (1954)
—E. J. Young, Studies in Isaiah (1954); Introduction to the OT, pp. 202-11 (1958); Who Wrote Isaiah? (1958); and his commentary on Isaiah, III, App. I, “The Authorship of Isaiah,” pp. 538-49 (posthumous, 1972)
—Rachel Margalioth, The Indivisible Isaiah (1964)
—Gleason L. Archer, A Survey of OT Introduction, pp. 317-39
—R. K. Harrison, Introduction to the OT, pp. 764-95 [but calls “Cyrus” text a gloss, pp.794-95](1969)
—Victor Buksbazen, The Prophet Isaiah (1971)
—J. Ridderbos, Isaiah (Bible Student’s Commentary; (1985)