soft-cover book vs soft-cover

soft-cover book and soft-cover both are nouns.

Word	Noun	Adjective	Verb	Adverb
soft-cover book	Yes	No	No	No
soft-cover	Yes	No	No	No

As nouns, soft-cover book and soft-cover are synonyms defined as:

Other synonyms of soft-cover book include paper-back book, paperback, paperback book, softback, softback book.

soft-cover book (noun)	soft-cover (noun)
a book with paper covers	a book with paper covers