por Levens, A. S. (Alexander Sander), 1900- [autor] | Paniagua Bocanegra, Francisco [traductor] | Levens, A. S. (Alexander Sander), 1900-. Graphics.
por Levens, A. S. (Alexander Sander), 1900- [autor] | Pérez Vázquez, Fernando Roberto [traductor] | Cooper, S. J. (Steven J.) [autor] | French, Thomas Ewing, 1871-1944 | Levens, A. S. (Alexander Sander), 1900-. Problems in mechanical drawing.