based on an extensive outline by Heinlein, was published in September 2006. Four collections have been published posthumously. Series Over the course of his career, Heinlein wrote three somewhat overlapping series: Future History series Lazarus Long series The Heinlein juveniles Early work, 1939–1958 Heinlein began his career as a writer of stories for Astounding Science Fiction magazine, which was edited by John Campbell. The science fiction writer Frederik Pohl has described Heinlein as "that greatest of Campbell-era sf writers". Isaac Asimov said that, from the time of his first story, the science fiction world accepted that Heinlein was the best science fiction writer in existence, adding that he would hold this title through his lifetime. Alexei and Cory Panshin noted that Heinlein's impact was immediately felt. In 1940, the year after selling 'Life-Line' to Campbell, he wrote three short novels, four novelettes, and seven short stories. They went on to say that "No one ever dominated the science fiction field as Bob did in the first few years of his career." Alexei expresses awe in Heinlein's ability to show readers a world so drastically different from the one we live in now, yet have so many similarities. He says that "We find ourselves not only in a world other than our own, but identifying with a living, breathing individual who is operating within its context, and thinking and acting according to its terms." The first novel that Heinlein wrote, For Us, the Living: A Comedy of Customs (1939), did not see print during his lifetime, but Robert James tracked down the manuscript and it was published in 2003. Though some regard it as a failure as a novel, considering it little more than a disguised lecture on Heinlein's social theories, some readers took a very different view. In a review of it, John Clute wrote: I'm not about to suggest that if Heinlein had been able to publish [such works] openly in the pages of Astounding in 1939, SF would have gotten the future right; I would suggest, however, that if Heinlein, and his colleagues, had been able to publish adult SF in Astounding and its fellow journals, then SF might not have done such a grotesquely poor job of prefiguring something of the flavor of actually living here at the onset of 2004. For Us, the Living was intriguing as a window into the development of Heinlein's radical ideas