Author

Welton J. Crook

3 books found

Cover of Abacus arithmetic

Abacus arithmetic

Welton J. Crook · First published 1958

Placeholder cover for Metallurgical spectrum analysis

Metallurgical spectrum analysis

Welton J. Crook · First published 1935

Placeholder cover for Table of arc spectrum lines arranged in order of wave length

Table of arc spectrum lines arranged in order of wave length

Welton J. Crook · First published 1933