Where do I place citations I'm writing a math paper using TexShop that is almost entirely original but I got help with a trig proof; I found a formula in a book that I improved upon, and then got help finding a number series that completed my improvement. I would like to cite the help I got and at least one book but I don't know the proper place to put citations, inline or at the end of the paper. Do I do

1) statement....

citation

more statements

or 

2)Topic

statements....statements

topic 

statements

last statement of paper

all citations
While the details are dependent on the venue where you are publishing, most mathematical papers will put the full citations at the end but reference them in the midst of the text (e.g., via a citation number).

You can format these automatically if you use LaTeX, and the AMS provides widely used packages for formatting.