The term 'FERBER BOOK' is a reference to the book 'Sleeping Through the Night: How Infants, Toddlers, and Their Parents Can Get a Good Night's Sleep' by Dr. Richard Ferber. The book is a guide for parents on how to help their children get a good night's sleep. The crossword solutions for this term are GIANT (5 letters) and SOBIG (5 letters). GIANT is an adjective that means very large or immense in size, while SOBIG is an adverb that means very big or large. Together, these two words describe the impact that Dr. Ferber's book has had on the parenting community.