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: We describe a 42 - year - old woman who developed superior sagittal and left transverse sinus thrombosis associated with prolonged epsilon - aminocaproic acid therapy for menorrhagia .
### Output Text:
We describe a 42 - year - old woman who developed superior sagittal and left transverse sinus thrombosis associated with prolonged <span class="chemical">epsilon - aminocaproic acid</span> therapy for menorrhagia . 