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: METHODS : In the population based , nationwide Swedish Inpatient Register a cohort of 1065 patients with Wegener ' s granulomatosis , 1969 - 95 , was identified .
### Output Text:
METHODS : In the population based , nationwide Swedish Inpatient Register a cohort of 1065 patients with Wegener ' s granulomatosis , 1969 - 95 , was identified . 