Pictured is the cover of "Goodnight Songs." Amazon

A collection of poetry written by "Goodnight Moon" author Margaret Wise Brown was published this month in a book entitled "Goodnight Songs."

The release by Sterling Publishing of the new children's book comes more than 65 years after Brown's "Moon" was first released.

"Goodnight Moon," one of the most popular children's books, was first published in 1947 and its author Margaret Wise Brown died a few years later in 1952. Before the Brooklyn native died of embolism, she hid a collection of poetry at her sister's barn in Vermont, which wasn't looked at until over 30 years later.

Publisher Amy Gary finally got the chance to read the poetry when she visited Brown's sister, Roberta Rauch, in Vermont. Rauch told Gary that these poetry manuscripts, about 60 of them, had been stored inside the trunk inside her barn.

Margaret Wise Brown is pictured in this undated publicity still. Consuelo Kanaga/HarperCollins

Although the manuscripts came out from hiding in 1989, they weren't able to be released until now. Often Brown would reuse lyrics from her other books, Gary found, which made discovering the rights to the lines a timely task. After many years, Gary was able to figure out the legalities of Brown's unpublished work and help put it together into a collection. "Goodnight Songs," published March 4, is now available, and Brown's original manuscripts are being kept at Hollis University's Wyndham Robertson Library.