Vintage 1949 Set of 4 National Wildlife Federation Illustrated Children's Book

Vintage 1949 Set of 4 National Wildlife Federation Illustrated Children's Book. Each book approximately 32 pages, size is 6.5 x 8.5 inches. See pics for book titles. Good Vintage condition, some wear and page tanning. See pics for condition. Book titles in set: Raindrops and Muddy Rivers Nature's Bank - The Soil Plants and Animals Live Together Would You Liked to Have Lived When?