A History of the Logarithmic Slide Rule and Allied Instruments, ...
Florian Cajori
The Language and Thought of the Child
Jean Piaget
Elements of Algebra
Leonhard Euler
A Short Introduction to Marcus Aurelius
John Lord
A Refutation of Moral Relativism: Interviews With an Absolutist
Peter J. Kreeft
Science, Mind and the Universe: An Introduction to Natural Philosophy
Helmut Moritz