If you are submitting a manuscript to a journal requiring ASA style it is a good idea to read the ASA Style Guide. It includes detailed content about usage: including vocabulary, syntax, punctuation, spacing, font size. It is more than just citations, although these are obviously critical.
If you don't want to buy a copy of the style guide, you can start by using the edition in the Internet Archive as a reference, linked here.
This guide is a guide. For confirmation, consult your instructor or the 6th edition of the American Sociological Association Style Guide.
ASA style follows the author-date system, (last name of the author or authors, followed by year of publication), established by the Chicago Manual of Style. The style consists of an in-text citation enclosed in parentheses, and a reference list at the end of the article, preceding any appendices.
The in-text citation is composed of author surname (s) and date of publication inside parentheses. For example (Kittredge 1980)
(If you are preparing a book manuscript, you will also need to include a bibliography, but you can cross that bridge when you come to it. This guide describes the author-date/ reference list system.)
☞ If you are quoting or referring to a specific passage, the in-text citation should include page numbers as well as the author and date.
When you have to include page numbers, use this format: year of publication- colon-page number(s), as below:(Thompson 2007:86)
Weird but true.
☞ If you use the author's name in the passage of text, don't include it in the in-text citation. Only include the year of publication; for example:
"as described by Thompson (2007), the effect of expectation is powerful...".
☞ Author's name not in the passage of text? Include it inside the parentheses, as below:
"The effect of expectation on measures of success has been found to be powerful (Thompson, 2007)". [Notice the parentheses are NOT set off by commas.]
☞ Multiple authors? If there are two, use both surnames connected by "and".
If there are three, use all three surnames in the first instance of the in-text citation, after that use et al. when citing the same authors.
"The effect of expectation on measures of success has been found to be powerful (Thompson, Carter and Walling 2007)
"Despite their perception of expectations, first-gen students were found to succeed... (Thompson et al. 2007)
Four or more authors? List the last name of only the first author followed by “et al.” and the year in every in-text citation.
"The effect of expectation on measures of success has been found to be powerful (Thompson et al. 2007)..." [Notice the period after et al.]
☞ More than one publication date? If you are citing material that has been reprinted use both publication dates. Include the earliest publication date in brackets, followed the date of the publication you are using.
"The effect of expectation on measures of success has been found to be powerful (Thompson  2007)..."
☞ Material not published yet? Use the word "Forthcoming". If it is a dissertation, include a date if available. If no date is available use N.d instead.
"A study concluded by Thompson (forthcoming) supports findings by Carter (N.d) showing that"...
☞ Multiple sources cited for the same statement? List them either in alphabetical order by author name OR by order of dates, but just be consistent. Separate them with a semi-colon.
(Thompson, 2007; Carter 1995; Walling 1987)
Forgoing adapted from American Sociological Association Style Guide, 4th Edition, 2010. Retrieved from Internet Archive, February 11, 2022.