Final answer:
The statement that an assignment should include only one source in the reference list if only one article is used is false; multiple credible sources should be cited to support the research and to avoid plagiarism.
Step-by-step explanation:
The assertion that an assignment using one article as a source should only include one source in the reference list is false. Any academic or professional assignment generally requires one to consult and cite multiple credible sources, even if the paper is primarily focused on a single source.
To substantiate the content, three to five reliable sources are suggested, which could range from academic journals and government publications to reputable websites and visual sources like TED Talks. Sources with clear bias or less credibility might help in locating more authoritative sources, by using the keywords from these to search in academic databases. The most important aspect to remember is that researchers must correctly cite sources to avoid the serious issue of plagiarism.