Barclay

William Barclay, The Letter to the Hebrews (Second Edition; The Daily Study Bible; Edinburgh: Saint Andrew Press, 1955, 1957)

BDAG

A Greek-English Lexicon of the New Testament and Other Early Christian Literature by Walter Bauer and Frederick William Danker, (Third Edition; based on previous English editions by W.F. Arndt, F.W. Gingrich, and F.W. Danker; University of Chicago Press, 1957, 1979, 2000). ISBN 0226039331. The modern standard NT Greek lexicon.

Bruce

F.F. Bruce, The Epistle to the Hebrews (New International Commentary on the New Testament, Revised Edition; Eerdmans, 1990). ISBN 0802823165

Ellingworth

Paul Ellingworth, Commentary on Hebrews (New International Greek Testament Commentary; Eerdmans, 1993). ISBN 080282420X

Guthrie

Donald Guthrie, Letter to the Hebrews (Tyndale New Testament Commentaries; Eerdmans, 1983). ISBN 0802814271

Hawthorne

Gerald F. Hawthorne, "The Letter to the Hebrews," in A New Testament Commentary, G.C.D. Howley, (General Editor) (Zondervan: 1969), pp. 533-566.

ISBE

The International Standard Bible Encyclopedia, Geoffrey W. Bromiley (general editor), (Eerdmans, 1979-1988; fully revised from the 1915 edition). ISBN: 0802837859. Excellent 4-volume scholarly, evangelical Bible dictionary.

Lidell-Scott

Henry George Liddell and Robert Scott, A Greek-English Lexicon (revised and augmented by Sir Henry Stuart Jones with the assistance of Roderick McKenzie; Oxford: Clarendon Press,1940). This standard Greek lexicon is available online as part of the Perseus Digital Library.

NIDNTT

New International Dictionary of New Testament Theology, Colin Brown (editor; Zondervan, 1975-1978; translated with additions and revisons from Theologisches Begriffslexikon zum Neuen Testament, Coenen, Beyreuther, and Bitenhard, editors), ISBN 0310332389. 

Robertson

A.T. Robertson, Robertson's Word Pictures  of the New Testament (Broadman Press 1932-33, 1960). ISBN 0805490558

Stedman

Ray C. Stedman, Hebrews (IVP New Testament Commentary Series; InterVarsity Press, 1992), ISBN 0830818154

TDNT

Theological Dictionary of the New Testament, Gerhard Kittel and Gerhard Friedrich (editors), Geoffrey W. Bromiley (translator and editor), (Eerdmans, 1964-1976; translated from Theologisches Wörterbuch zum Neuen Testament, ten volume edition). CD-ROM, ISBN 1577990994. Standard for many years, mixture of conservative and liberal treatments of NT Greek words.

Thayer

Joseph Henry Thayer, Greek-English Lexicon of the New Testament (Associated Publishers and Authors, n.d., reprinted from 1889 edition). Often includes derivations of compound words.

Vincent

Marvin R. Vincent, Word Studies in the New Testament (second edition 1888; reprinted: Associated Publishers and Authors, 1972)

Westcott

Brooke Foss Westcott, The Epistle to the Hebrews (Eerdmans, 1970, reprinted from the second edition, 1892).