What If? – Mind–Boggling Science Questions for Kids Autor R Ehrlich 26 apr 1998 Paperback Preț: 95.50 lei 3-5 săpt. | 7-13 zile
Turning the World Inside Out and 174 Other Simple Physics Demonstrations Autor R Ehrlich 30 iun 1992 Paperback Preț: 239.66 lei 6-8 săpt.