The Harvard Referencing System is one of the preferred layouts for these references. It is a relatively strict way of arranging the bibliographical information.
Harvard referencing style (also known as author-date style) is a generic description for any that uses in-text citations with an author and date. In that sense, is a type of Harvard referencing. However, many individual styles describe themselves as Harvard. They vary from source to source in small details (such as reference punctuation).
UWE Bristol Harvard referencing style - UWE Bristol: …
Vancouver style is sometimes used in science journals, for example. This style uses a number to represent each source, and lists the sources in the reference list in the order they were used.