the Origin of Indo Iranians: 3 (Leiden European Etymological Dictionary)

Etymological Dictionary of Greek (2 Vols.): 10 (Leiden Indo European Dictionary)

Etymological Dictionary of the Iranian Verb (Leiden Indo European Series): 2

Etymological Dictionary of Proto celtic: 9 (Leiden Indo European Series)

Etymological Dictionary of Greek, 2 Volume Set (Leiden Indo European Dictionary): 10