

A number is allocated to a source in the order in which it is first cited in the text. If the source is referred to again, the same reference number is reused.

A number must be used even if the author(s) is named in the sentence/text.

A number is allocated to a source in the order in which it is first cited in the text. If the source is referred to again, the same reference number is reused.
A number must be used even if the author(s) is named in the sentence/text.