. . . . . . . . . "Designing and making : a book for boys, girls and inventors" . "Designing and making"@en . . "Designing and making" . "Designing and making : A book for boys and girls inventors" . . . . "Designing and making; a book for boys, girls and inventors"@en . . . . . . . . . "Problems and exercises"@en . . . "Juvenile works"@en .