When using information from another source you must give credit to the original author or you are plagiarizing. You give credit by citing the source. Make sure your citation contains everything you would need to backtrack and find the information again. It is best to pick one citation style and be consistent.
In addition to providing guidance on grammar, the mechanics of writing, and APA style, this manual offers an authoritative reference and citation system. It also covers the treatment of numbers, statistical and mathematical data, tables and figures.