Citations are a vital part of the research process. They allow the reader to locate sources used as part of your research, lend credibility to your argumentation, and demonstrate your ability to participate in a scholarly dialogue. Proper citations also give credit to the original authors of the sources or ideas you are using. Without these citations, it is impossible to avoid plagiarism.
The disciplines of Physics and Astronomy use either APA (American Psychological Association) Style or MLA (Modern Language Association) Style. To be sure you are using the correct style, check with your professor.
APA (American Psychological Association) Style, 7th Edition
Resources for Learning about APA
Quick Guides for Formatting Citations Using APA
MLA (Modern Language Association) Style, 8th Edition
Resources for Learning about MLA
Quick Guides for Formatting Citations Using MLA