Princípio dos trabalhos virtuais (Portuguese Wikipedia)

Analysis of information sources in references of the Wikipedia article "Princípio dos trabalhos virtuais" in Portuguese language version.

refsWebsite

Global rank Portuguese rank

2books.google.com

3^rd place

6^th place

books.google.com

C. Lánczos, The Variational Principles of Mechanics, 4th Ed., General Publishing Co., Canada, 1970
W. Yourgrau and S. Mandelstam, Variational Principles in Dynamics and Quantum Theory, 3rd Ed., General Publishing Co., Canada, 1968