One idea is to define explicit document reference as follows:
If document D1 contains substring S (sentence or quote) from document D2 and source or author of D2 is mentioned in D1 within a window of N sentences to the left and to the right of S, then D1 explicitly refers to D2. We can start with N=3.
For example:
D2 = {text='This is a great article!', source="BBC",author=}
D1 = {text='BBC wrote: "This is a great article!"'}
One idea is to define explicit document reference as follows:
If document D1 contains substring S (sentence or quote) from document D2 and source or author of D2 is mentioned in D1 within a window of N sentences to the left and to the right of S, then D1 explicitly refers to D2. We can start with N=3.
For example:
D2 = {text='This is a great article!', source="BBC",author=}
D1 = {text='BBC wrote: "This is a great article!"'}