Young-adult fiction or young adult literature, often termed as YA, is fiction written, published, or marketed to adolescents and young adults. The Young Adult Library Services Association (YALSA) of the American Library Association (ALA) defines a young adult as someone between the ages of twelve and eighteen. Authors and readers of young adult (YA) novels often define the category as literature traditionally written for ages ranging from sixteen years to the age of twenty-five, while Teen Fiction is written for the ages of ten to fifteen.The terms young-adult novel, juvenile novel, young-adult book, etc. refer to the works in the YA category.
The subject matter and story lines of YA literature are typically consistent with the age and experience of the main character, but YA literature spans the spectrum of fiction genres. YA stories that focus on the specific challenges of youth are sometimes referred to as problem novels or coming-of-age novels. ~ from Wikipedia
"Does anyone any longer know what we mean by the term young-adult literature? Not so long ago, I would have said, without too much fear of contradiction, that it meant book for readers from 12 to 18 years old. But, over the course of the last several years, the term has grown so restlessly expansive that it now seems to embrace titles for readers as young as 10 and (arguably) as old as 35." - Michael Cart; 2004
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A partial list of movies adapted from YA books
YALSA's Teen Book Finder is a free app to help teens, parents, librarians and library staff, educators, and anyone who loves YA literature access to the past three years' of YALSA's awards and lists on their smartphone.
The distant mirror : reflections on young adult historical fiction by 
From Hinton to Hamlet : building bridges between young adult literature and the classics by 
Young adult literature in the classroom : reading it, teaching it, loving it by REFERENCE RESOURCE
Booklist's 1000 best young adult books since 2000 by MORE eBOOKS
Critical foundations in young adult literature : challenging genres by 
Immigration narratives in young adult literature : crossing borders by Includes journal titles and articles
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