Reference

For example:

1. Older workers were more likely to feel 'unskilled', yet ·they were least likely to take up formal training. [they = older workers]
2. Finally, the tea is dried in an oven and this stops the oxidation process. [this = dried in an oven]
3. Women had a lower literacy rate than men.This was most noticeable in developing nations. [this = Women had a lower literacy rate than men]

Pronouns can refer to a noun phrase, as in sentence 1; a verb phrase, as in sentence 2; or a whole sentence, as in sentence 3.