Halliday & Matthiessen (2014: 607):
The cohesive resources make it possible to link items of any size, whether below or above the clause; and to link items at any distance, whether structurally related or not. Many instances of cohesion involve two or three ties of different kinds occurring in combination with one another. For example:‘You don’t know much,’ said the Duchess; ‘and that’s a fact.’
Alice did not at all like the tone of this remark, and thought it would be as well to introduce some other subject of conversation.
where the nominal group this remark consists of a reference item this and a lexical item remark, both related cohesively to what precedes. Similarly in some other subject of conversation, both other and subject relate cohesively to the preceding discussion, which was about whether or not cats could grin. Typically any clause complex in connected discourse will have from one up to about half a dozen cohesive ties with what has gone before it, as well as perhaps some purely internal ones like the that by which the Duchess refers back to the first part of her own remark.