Clifford D. Simak & S. H. Marpel 
Clifford D. Simak: Golden Age Space Opera Tales [EPUB ebook] 

Clifford Donald Simak (August 3, 1904 – April 25, 1988) was an American science fiction writer. He won three Hugo Awards and one Nebula Award. The Science Fiction Writers of America made him its third SFWA Grand Master, and the Horror Writers Association made him one of three inaugural winners of the Bram Stoker Award for Lifetime Achievement.
Simak continued to produce award-nominated novels throughout the 1950s and 1960s. Aided by a friend, he continued writing and publishing science fiction and, later, fantasy, into his 80s. He believed that science fiction not rooted in scientific fact was responsible for the failure of the genre to be taken seriously, and stated his aim was to make the genre a part of what he called "realistic fiction."
Space Opera is a subgenre of science fiction that emphasizes space warfare, melodramatic adventure, interplanetary battles, chivalric romance, and risk-taking. Set mainly or entirely in outer space, it usually involves conflict between opponents possessing advanced abilities, futuristic weapons, and other sophisticated technology.
The term has no relation to music, as in a traditional opera, but is instead a play on the terms "soap opera", a melodramatic television series, and "horse opera", which was coined during the 1930s to indicate a formulaic Western movie. Space operas emerged in the 1930s and continue to be produced in literature, film, comics, television, and video games.
The Golden Age of Pulp Magazine Fiction derives from pulp magazines (often referred to as "the pulps") as they were inexpensive fiction magazines that were published from 1896 to the late 1950s. The term pulp derives from the cheap wood pulp paper on which the magazines were printed. In contrast, magazines printed on higher-quality paper were called "glossies" or "slicks". (Wikipedia)
The pulps gave rise to the term pulp fiction. Pulps were the successors to the penny dreadfuls, dime novels, and short-fiction magazines of the 19th century. Although many writers wrote for pulps, the magazines were proving grounds for those authors like Robert Heinlein, Louis La Mour, "Max Brand", Ray Bradbury, Philip K. Dick, and many others. The best writers moved onto longer fiction required by paperback publishers. Many of these authors have never been out of print, even long after their passing.
Anthology containing:
Message From Mars
The World That Couldn't Be
Hellhounds of the Cosmos
The Street That Wasn't There (with Carl Jacobi)
Project Mastodon
The Shipshape Miracle
Second Childhood
Empire
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