A more thorough explanation:

Definition: S.P. is an abbreviation that can have two meanings:

1. SINE PROLE: This Latin phrase means "without offspring." It is used in genealogy to indicate that a person did not have any children.
2. Same principle; same point: This notation is used between two citations to indicate that the second citation involves the same principles as the first.

Example:

If we have two articles that discuss the same topic, we can use S.P. to show that they have the same principles. For instance:

Article 1: "The Benefits of Exercise for Mental Health." (Smith, 2021)

Article 2: "The Relationship Between Exercise and Mental Health." (Jones, 2022) S.P. Smith (2021)

In this example, the S.P. notation indicates that Jones' article is discussing the same principles as Smith's article.