A previously unpublished book written by Dr. Seuss is in stores today, over 20 years after his death.

Time is reporting the book titled "What Pet Should I Get" is the first book published by Dr. Seuss in over 20 years. The book was written sometime in the 1950s to 1960s according to USA Today.

The plot of the story is very simple: A brother and a sister go to a pet store and choose one pet by noon. The kids have a hard time choosing one pet. The brother wants a dog and the sister wants a cat. The story has the same brother and sister from Dr. Seuss's "One Fish, Two Fish, Red Fish, Blue Fish."

The book has gotten rave reviews. Time gave the book a "three stars out of four" for "mundane rhymes and a less-than-fantastical plot."

This book isn't the only book possibly written in the late 1950s to recently come out. Harper Lee's "Go Set A Watchman," an unedited first draft of "To Kill a Mockingbird," is a instant best seller after its release earlier this month. The book has caused a bit of controversy for it's shocking portrayal of Atticus Finch as a racist.

Dr. Seuss, who passed away in 1991, released his last book in 1990, titled "Oh, The Places You'll Go." Throughout his career, Dr. Seuss has created timeless classics, such as "The Cat in the Hat," "Green Eggs and Ham" and "Horton Hears a Who." "What Pet Should I Get" has been published by Random House Publishing. 

Some of his classics were made into movies, with "The Lorax" most recently debuting in 2012. "Cat in the Hat" was made into a film starring Mike Myers in 2003. The film did very well in the box office, making $134 million dollars.