Parmenides
The Fragments ... / A.H. Coxon
2nd ed. Parmenides Press, 2009
Parmenides Lehrgedicht; griechisch und deutsch / Hermann Diels
Berlin: Reimer, 1897
Fragmenta DK 1922 edition Perseus Digital library

Parmenides : being, bounds, and logic / Scott Austin.
Yale University Press, 1986
By being, it is:  the thesis of Parmenides / Néstor-Luis Cordero.
Las Vegas: Parmenides, 2004
The Route of Parmenides / A.P.D. Mourelatos
2nd ed. Parmenides Press, 2008
Parmenides and presocratic philosophy / John Palmer
Oxford University Press, 2009

Empedocles

Empedokles Physika I eine Rekonstruktion des zentralen Gedankengangs / Oliver Primavesi
De Gruyter, 2008
Empedocles, the extant fragments / M. R. Wright
Bristol Classical Press, 1995
 

Early Greek philosophy /André Laks and Glenn W. Most
Loeb Classical Library (Harvard University Press, 2016)
v.1 Introductory &  Reference Materials
v.2  Beginnings &  Early Ionian Thinkers, Part 1
v.3 Early Ionian Thinkers, Part 2
v.4 Western Greek Thinkers, Part 1
v.5 Western Greek Thinkers, Part 2
v.6 Later Ionian & Athenian Thinkers, Part 1
v.7  Later Ionian and Athenian Thinkers, Part 2
v.8  Sophists, Part 1
v.9 Sophists, Part 2.