Reference grammars to buy and own physical copies of:
-Smyth
-BDF
–A Grammar of the Greek New Testament in the Light of Historical Research by A.T. Robertson
–A Syntax of Septuagint Greek by T. Muraoka
–An Historical Greek Grammar Cheifly of the Attic Dialect as Written and Spoken from Classical Antiquity Dow to the Present Time by A.N. Jannaris