How and Why Wonder Book - lot 4 Building Atomic Energy, Flight, Caves VTG 1960s

This bundle of 4 vintage 60s softcover books are from the How and Why Wonder Book Library. All show signs of wear, and have pages that are yellowing with age. Overall fair condition. 1. Building 5051 - 1964 2. Caves and SKyscrapers 5043 - 1963 Mark inside front cover, light pencil scribbles inside back cover. 3. Flight 5019 - 1961 More wear to cover than average including crayon mark, pencil drawing. Binding starting to loosen from cover 4. Atomic Energy 5015 - 1961 COver has bend mark. Cover loose from book (pages still well bound). Edges of pages have indents in several areas.