As John Lange

Between 1966 and1972 Michael Crichton published eigtht novels under the pseudonym John Lange.

             

           

Within months of being published, Binary (1972) would be made into a movie under the title of Pursuit (1972).

Easy Go (1968) would be republished under the title The Last Tomb in 1974.

Hardcase Crime began to reprint them as a collection in the 2000s, beginning with Grave Descend in 2006. Zero Cool followed in 2008 with new material written by Michael Crichton shortly before his death, which truncated the reprinting of the series until it was resumed in 2013 (see below)

         

All Eight John Lange Novels were reprinted as paperbacks by Hardcase Crime on October 29, 2013,  but now with "Michael Crichton writing as...". As can be seen, Grave Descend and Zero Cool had otherwise identical covers:

      

      

They were published as an e-book collection in 2020:

And in 2023 they have been published again as "The Med School Years collection" by Blackstone publishing in collaboration with CricthonSun:

(video from Blackstone Publishing)

As Jeffery Hudson

In 1968 he published the novel A Case of Need as Jeffery Hudson. It would be made into the Movie The Carey Treatment (1972) and re-published under his own name in 1993.

   

As Michael Douglas

With his brother Douglas, Michael Cricthon wrote the novel Dealing Or The Berkeley-to-Boston Forty-Brick Lost-Bag Blues in 1970, under the pseudonym made by putting their two first names together. Playboy magazine published it in three installments in its December 1970, January 1971 and February 1971 issues.
It also became a film under the same title in ... yes, you guessed it: 1972.