"Perilous Plan of the Plant-Master" and "Fury of the Floronic Man!" by Denny O'Neil (in English)

art by Dick Dilin and Terry Austin.

"Perilous Plan of the Plant-Master" - The Flash #245 - DC Comics, November 1976.
"Fury of the Floronic Man!" - The Flash #246 - DC Comics, January 1977.

"Let There Be...Darkness!" by Denny O'Neil (in English)

 art by Mike Grell and Bill Draut - The Flash vol.1 #237 - DC Comics, August 1975.

 

"The Call of the Cosmos" by Cary Burkett (in English)

 art by Joe Staton - Adventure Comics vol.1 #459 - DC Comics, October 1978.