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Another great reference book similar to the Pocket Ref. Engineering Formulas focuses heavily on math, engineering, and science. This book contains sets of constants and formulas for a wide range of problems. Unlike the Pocket Ref the information in Engineering Formulas is aimed more at scientists and engineers instead of construction workers and mechanics.
I found this a handy reference to have while working on my physics degree as it provides a single reference for a large amount of mathematics formulas. Covering information from basic arithmetic up to differential equations and integral calculus. Normally you might need a dedicated reference for each one.
Once you have passed the math sections you enter the engineering sections. Here you will find constants and formulas for statics, dynamics, hydraulics, and machine parts. Engineering Formulas even devotes sections to more in depth information for production, electrical, and control engineering.
Finally, the book finishes its collection with chemistry and radiation physics. The end appendix being full of tables of constants for anything from friction coefficients to solutions to statistics equations for known values.
Overall I would recommend this to anyone studying engineering or physics as a quick all in one reference. Not only is there a vast wealth of existing information in this book, there are also many blank pages where you can add more.