source book vs reference work

source book and reference work both are nouns.

Word	Noun	Adjective	Verb	Adverb
source book	Yes	No	No	No
reference work	Yes	No	No	No

As nouns, reference work is a hypernym of source book; that is, reference work is a word with a broader meaning than source book:

source book: a collection of historically important documents published together as a book
reference work: a book to which you can refer for authoritative facts

Other hypernyms of source book include book of facts, reference, reference book.

source book (noun)	reference work (noun)
a collection of historically important documents published together as a book	a book to which you can refer for authoritative facts