Enciclopédia da ciência 2 / Dorling Kindersley; coord.edit.: Susana KcKeever, Sophie Mitchell; coord.art.: Martyn Foote, Miranda Kennedy
Problemes : Méthodes et stratégies de résolution / Pierre Gaspar
Speech and Hearing / Harvey Fletcher
Sampling inspection tables : Single and double sampling / Harold F. Dodge; Harry G. Romig