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: Cardiac function was assessed in long - term survivors of malignant bone tumors who were treated according to Rosen ' s T5 or T10 protocol , both including doxorubicin .
### Output Text:
Cardiac function was assessed in long - term survivors of malignant bone tumors who were treated according to <span class="chemical">Rosen ' s T5 or T10 protocol</span> , both including <span class="chemical">doxorubicin</span> . 