reference

Reference is a relation between objects in which one object designates, or acts as a means by which to connect to or link to, another object

Reference is a relation between objects in which one object designates, or acts as a means by which to connect to or link to, another object. The first object [...]

A circular reference is a series of references where the last object references the first, resulting in a closed loop

A circular reference is a series of references where the last object references the first, resulting in a closed loop.A circular reference is not to be [...]

A citation, or reference,[1] uniquely identifies a source of information:Wikipedia

A citation, or reference,[1] uniquely identifies a source of information:Wikipedia's Verifiability policy requires inline citations for any material [...]

Product placement, brand integration or embedded marketing,[1][2][3][4] is, according to the The US Government

Product placement, brand integration or embedded marketing,[1][2][3][4] is, according to the The US Government "any form of audio-visual commercial [...]