The Principles of Language-Study
Principles of Home Decoration, With Practical Examples
Principles of Freedom
The Principles of Economics, with Applications to Practical Problems
Principles of Decorative Design
The Principles of Chemistry, Volume II
The Principles of Chemistry, Volume I
The Principles of Breeding
The Principles of Biology, Volume 2 (of 2)
The Principles of Biology, Volume 1 (of 2)
The Principles of Aesthetics
The Principle of Relativity
Principle and Practice: The Orphan Family
Principios e questões de philosophia politica (Vol. II)
La Principessa
Principes de la Philosophie de l'Histoire