Not peer-reviewed: This work has not been scrutinised by independent experts, or the story does not contain research data to review (for example an opinion piece). If you are reporting on research ...

Peer-reviewed: This work was reviewed and scrutinised by relevant independent experts. Observational study: A study in which the subject is observed to see if there is a relationship between two or ...

Peer-reviewed: This work was reviewed and scrutinised by relevant independent experts. Observational study: A study in which the subject is observed to see if there is a relationship between two or ...

Peer-reviewed: This work was reviewed and scrutinised by relevant independent experts. Observational study: A study in which the subject is observed to see if there is a relationship between two or ...

Peer-reviewed: This work was reviewed and scrutinised by relevant independent experts. International researchers have figured out the makeup of a "phantom chemical" found in some drinking water, over ...

Peer-reviewed: This work was reviewed and scrutinised by relevant independent experts. Thanks to us humans, many of Earth’s oldest, often largest, and most experienced animals are being wiped out from ...

Peer-reviewed: This work was reviewed and scrutinised by relevant independent experts. Observational study: A study in which the subject is observed to see if there is a relationship between two or ...

Peer-reviewed: This work was reviewed and scrutinised by relevant independent experts. Meta-analysis: This type of study involves using statistics to combine the data from multiple previous studies to ...

Peer-reviewed: This work was reviewed and scrutinised by relevant independent experts. Systematic review: This type of study is a structured approach to reviewing all the evidence to answer a specific ...

Peer-reviewed: This work was reviewed and scrutinised by relevant independent experts. Systematic review: This type of study is a structured approach to reviewing all the evidence to answer a specific ...

Peer-reviewed: This work was reviewed and scrutinised by relevant independent experts. Randomised controlled trial: Subjects are randomly assigned to a test group, which receives the treatment, or a ...