"The research worker, in his efforts to express the fundamental laws of Nature in mathematical form, should strive mainly for mathematical beauty. He should take simplicity into consideration in a subordinate way to beauty ... It often happens that the requirements of simplicity and beauty are the same, but where they clash, the latter must take precedence." ~ Paul Dirac
I use a lot of books for reference in my research. Many books of this type lend themselves to not direct reading but more as reference to flip through for specific needs. This book does both those things. Over the past year I cannot think of a book which I have both consulted more, on a wide array of topics or enjoyed more as reading on topics of general interest. Even if you're not writing in C, due to C being the progenitor language of most common languages used today, the code in this book makes for great sudo code.
I found the sections of pade approximants, moments of distribution (statistics chapter) and the section of random numbers to be both well written and adequately explored.
"What we know is not much. What we do not know is immense." ~ Pierre Simone Laplace