You should always try to find a date for your sources. Most reliable sources of information will have a date - either a date for when the source was published, or a date for when it was last updated.
If you genuinely cannot find a date, and you must cite this work, use "date unknown" in place of the year.
If you genuinely cannot find a date, and you must cite this work, omit published date and use the updated date and date accessed.
A quote that would go close two or over lines of text (usually about 40 words) is best treated as a block quote. Instead of quoting in-line with the text and using quotation marks, it is moved to a new line and the entire quote is off-set (indented) one tab mark.
In discussing the expression of Othello syndrome in dementia patients, Cipriani et al. noted that:
Morbidly jealous individuals interpret conclusive evidence of infidelity from irrelevant occurrences, refuse to change their beliefs even in the face of conflicting information, and tend to accuse the partner of infidelity with many others.1(p.188)
Note: For undergraduate papers, page numbers are included with the in-text citation number for direct quotes. Papers published in journals might not have page numbers for in-text citations.
You can read more about AMA's recommendations for formatting block quotes by following the link below.
In the medical sciences, you should only use a direct quote if the exact wording is important. You should be paraphrasing the information as much as possible. When paraphrasing, it is not standard practice to use page numbers, but they can be used if you feel it is necessary for clarification.
However, if you do need to refer to the exact wording used by the authors, you must put the quote in "quotation marks" and use a page number next to the in-text citation.
You put the page number in brackets directly after the reference number, with no space: 1(p6). This all goes in superscript.
Articles are sometimes published online in advance of their appearance in the actual journal.
If you find an article that is "in press" or an "advance online publication", first check to see you have the latest version of that article.
Cite it as you would a journal article, including all information available (you may not have the volume, issue or page numbers), and include published online Month DD, YYYY after the article title.
Note: One-word titles are never abbreviated, and the complete word in a title can always be used if an abbreviation cannot be found.
The current edition of the AMA manual does not specifically reference using URL shorteners, but previously the AMA style blog (AMA Style Insider) has stated that the use of shortened URLs for scientific publications is not encouraged. An assignment or thesis usually follows the same expectations as a published paper, but you can negotiate with your lecturer if they will accept shortened URLs if the work is not actually intended for publication.
"Using bit.ly to shorten URLs in the reference list for a scientific article is probably not consistent with best practices. We do use bit.ly in our style manual tweets, to save space, but the reference list of a scientific article is a different matter. Use of the full URL allows readers to know the original domain name (like nih.gov). We are also not sure how permanently stable a shortened link would be." https://amastyleinsider.com/2012/12/18/questions-from-users-of-the-manual-18/
You should always try to find volume and issue number for journal articles. However, some journals genuinely don’t have volume or issue numbers. If you have tried to find the information, and you simply cannot, then you skip that part of the pattern.
Note that you still use a colon before the page numbers.