Query regarding RQM Rest API (History Fetch) response

Hi,
 
We wanted to fetch the changes/history of the RQM Test Case artifact.

We are using following History Query for this purpose, we are referring this query format from  API Document document.

History API Query:
https://<Host>:9443/qm/service/com.ibm.rqm.integration.service.IIntegrationService/history?resourceId=resources/<project alias>/testcase/urn:com.ibm.rqm:testcase:14

Header:
 we have tried different Accept and content type header. we have tried following values  both for content type and accept header
application/xml;
application/json;
application/atom+xml;
etc.

API Response:
Response Link

This query seems to be working and giving us the all changes made to the given Test Case
but we have concern here is regarding the above API response.

We are getting response in XHTML format as referenced above.
Are we missing any thing in this query or any request header?

is there any way that we can get response of this history query in XML or Json form?

Kindly help us to address our query to fetch result in XML or Json format.

Thanks & Regards,
Ajay