Numbered styles list references in the order they are mentioned, using a digit in the text to refer to the fuller citation at the end.
The most common numbered style is Vancouver - while this style has its own particular rules, numbered styles in general are often referred to as Vancouver styles.
Here's our example in the Vancouver style:
In the text:
Blah blah blah (1).
1. McClimens A, Kenyon L, Cheung H. Exploring placement pathways in nurse education. British Journal of Nursing. 2013;22(1):8-15.