Author-date or numeric style


Basically there are two main citation styles for in-text citations: the author-date and numeric style. In the author-date style in-text citations give the surname(s) of the author(s) and the publication year. The reference list at the end of the document is ordered alphabetically by the surname of the first author. In the numeric style in-text citations are given a number (with superscript or bracketed numerals). The reference list is arranged numerically according to the order of appearance in the text. The numbers in the text refer to the numbers in the list. Within these styles there are many variations possible, especially on the level of the reference lists. Just have a look at the examples of three different journals:

Ecological Research

Ecological Research: in-text citation in author-date style
Ecological Research: in-text citation in author-date style

Ecological Research: alphabetical reference list
Ecological Research: alphabetical reference list

Nature

Nature: in-text citation with superscript numerals
Nature: in-text citation with superscript numerals

Nature: numeric reference list
Nature: numeric reference list

Science

Science: in-text citation with bracketed numerals
Science: in-text citation with bracketed numerals

Science: numeric reference list
Science: numeric reference list