When you are using information that was originally published in a source you have not read (e.g., quotes, statistics or data), but was cited in a source you have read, give the full citation details for both sources, using "Cited by:" (for information/data) or "Quoted by:" (for quotes) to join them.
NOTE: Generally speaking, you cite the work you have in front of you. The only reason why you would use a secondary citation would be if you were directly referring to the work or words of one author, but did not have access to the original.
What this looks like:
You have been reading a journal article by Winchester, which gives a quote by Smith and Wesson, and you want to use that quote. In your reference list, cite Smith and Wesson (complete reference) Quoted by: Winchester (complete reference).
Smith and Wesson1(p6) noted the "complete irrelevance of this kind of data" in advanced discussions of this nature.
In the reference list:
- Smith J, Wesson A. Information that could lead to confusion. Am J Adv Discuss. 1982;14(6):12-24. Quoted by: Winchester B. Reflections on information usage. Arch Aust Discuss. 2014;45(4):45-57.
Slobin1(p191) noted that children "pay attention to the ends of words," a factor that may favour the acquisition of nouns in English, which have simpler and more regular endings. Gentner2 argued that children of all language acquire verbs later than nouns.
In the reference list:
- Slobin DI. Cognitive prerequisites for the development of grammar. In: Ferguson CA, Slobin DI eds. Studies of Child Language Development. New York, NY: Holt, Rinehart, & Winston; 1973:175-208. Quoted by: Bornstein MH, Cote LR, Maital S, et al. Cross-linguistic analysis of vocabulary in young children: Spanish, Dutch, French, Hebrew, Italian, Korean, and American English. Child Dev. 2004;75(4):1115-1139. doi:10.2307/3696530.
- Gentner D. Why are nouns learned before verbs: linguistic relativity versus natural partitioning. In: Kuczaj S II ed. Language Development, Vol. 2: Language, Thought and Culture. Hillsdale, NJ: Erlbaum;1982. Cited by: Caselli C, Casadio P, Bates E. A comparison of the transition from first words to grammar in English and Italian. J Child Lang. 1999;26(01):69-111. doi:10.1017/S0305000998003687.
- Use secondary citations sparingly - if the work you have read is synthesising information from various sources, and you are paraphrasing their work, then you only need to cite the work you have read.
- Note that the Gentner reference in the reference list is missing page numbers (it didn't need page numbers in-text because it's not a direct quote). This is because the citation information given in Caselli, Casadio and Bates did not include page numbers and the information could not be found through other means. Always endeavour to find the complete citation details for the original work, if possible.
- Note also that the volume number for the book is not included after the title of the Gentner reference. This is because the volume number is part of the title, and AMA does not want it repeated if it is in the title.
- Here is the AMA Guide's entry for secondary citations.