Author: Donald Keith (pseudonym)
Alternate names: Donald Monroe; Keith Monroe
Title: pseud.
Bio: From [Wikipedia][1]:

Donald Keith was a pseudonym for authors Donald (1888–1972) and Keith Monroe (1917–2003). They are best known for their series of stories in the Time Machine series, which were originally published in Boys' Life magazine between 1959 and 1989. Some of the stories were combined into two books, Mutiny in the Time Machine (1963) and Time Machine to the Rescue (1967).


  [1]: https://en.wikipedia.org/wiki/Donald_Keith_%28author%29