Which of the following sentences in a research paper should include a citation?

"The last World Health Organization report states that asthma may become worse at night or with exercise"
This requires a citation as it contains a fact taken from another person/group’s report.

"Asthma symptoms include episodes of wheezing, coughing, chest tightness, and shortness of breath." => No citation is required here as asthma symptoms are generally considered common knowledge. In academic writing, the concept of “common knowledge” refers to information that an average educated reader would accept without needing the validation of a source reference.

"Opposite of the World Health Organization’s findings mentioned in section 2, this paper concludes asthma symptoms can be lessened with an exercise routine." => This sentence does not require a citation since it references findings given in the author’s own report.

"The present paper explores the relationship between asthma and exercising." => No citation is required here as the author is referencing their own work. Writers need to include citations when using data, ideas, images, etc. that are not their own.