Useful References for Mathematical Notations, Symbols, and Constants

https://en.wikipedia.org/wiki/Mathematical_notation

https://en.wikipedia.org/wiki/List_of_mathematical_symbols

https://en.wikipedia.org/wiki/Greek_letters_used_in_mathematics,_science,_and_engineering

https://en.wikipedia.org/wiki/List_of_letters_used_in_mathematics_and_science

https://en.wikipedia.org/wiki/ISO_31-11

https://en.wikipedia.org/wiki/Latin_letters_used_in_mathematics

https://en.wikipedia.org/wiki/List_of_mathematical_abbreviations

https://en.wikipedia.org/wiki/List_of_mathematical_symbols_by_subject

https://en.wikipedia.org/wiki/List_of_mathematical_constants

https://en.wikipedia.org/wiki/Notation_in_probability_and_statistics

https://en.wikipedia.org/wiki/Mathematical_operators_and_symbols_in_Unicode

https://en.wikipedia.org/wiki/Physical_constant

https://en.wikipedia.org/wiki/List_of_logic_symbols

https://en.wikipedia.org/wiki/Typographical_conventions_in_mathematical_formulae

http://functions.wolfram.com/Notations/
http://functions.wolfram.com/PDF/Notations.pdf