The NLM citation style was created by the National Library of Medicine. The recommended resource for this style is Citing Medicine: the NLM Style guide for Authors, Editors, and Publishers (2nd ed. 2007). This resource is only available electronically. Please click on the link listed below.
The Dental Hygiene Department has created a guide to using and formatting reference citations using the National Library of Medicine (NLM) style. Click on the link people to open the document.
When writing a research paper, you must give credit where credit is due.
...IMMEDIATELY CITE OR ACKNOWLEDGE THE SOURCE.
In DENH courses never quote material verbatim in your papers
There is not a rule of thumb of how many references you should have in your paper, but every time you take information from a source you need to cite it.
Also, you can use multiple references for the same sentence, see below.