Tom Hartley has been laboring on his hypothetical DC Archives series for much of this year, designing new front & back covers, tables of content, and even writing introductions under the pseudonym "Wade Greenberg." It must be nice for him that he only needed one biographies page for nearly the entire project, seeing as Jack Miller and Joe Certa were the only clearly documented creators for most of the Manhunter from Mars strip. Obviously Joe Samachson gets credit for co-creating the character and crafting his first few installments, while it's been argued that Dave Wood and perhaps others pitched in for Miller on later scripts. Though his art style varied broadly, there's little doubt Joe Certa drew every installment of John Johns' thirteen year run. You can download the PDF here.
Artist Joe Certa began his comics career in the mid-1940s. He worked for DC throughout the 1950s and 1960s, drawing the Robotman and Captain Compass back-up features in DETECTIVE COMICS, and every one of the John Jones, Manhunter from Mars stories, which ran in issues #225-326 and continued in HOUSE OF MYSTERY #143-173. Much of his later work was for Gold Key on various horror and mystery titles, including the comics adaptation of the TV show, Dark Shadows. Certa died in 1986.
Jack Miller was a DC editor from 1964-1969, handling such titles as STRANGE ADVENTURES, INFERIOR FIVE, MANIAKS, WONDER WOMAN and various romance titles. From the 1940s through much of the 1960s he also wrote comics, especially for DC, including such features as Deadman, Blackhawk, Aquaman, Batman, Jimmy Olsen, Congo Bill, and John Jones, Manhunter from Mars. He also wrote novels and nonfiction works, and some TV animation. Miller died in 1970.