In the sentence extracted from biomedical literature, identify all the chemical entities. The required answer format is the same sentence with HTML <span> tags to mark up specific entities. 
### Entity Markup Guides:
Use <span class="chemical"> to denote a chemical.

### Input Text: Reserpine - and haloperidol - induced orofacial dyskinesia are putative animal models of tardive dyskinesia ( TD ) whose pathophysiology has been related to free radical generation and oxidative stress .
### Output Text:
<span class="chemical">Reserpine</span> - and <span class="chemical">haloperidol</span> - induced orofacial dyskinesia are putative animal models of tardive dyskinesia ( TD ) whose pathophysiology has been related to free radical generation and oxidative stress . 