If you have the physical document you can scan or photograph it and upload the image. Just click on the Images tab and follow directions to upload. If you have the information, but not the actual document you can source it something like “State of New Hampshire, Department of Public Health, Death Certificate, Joe B. Parks, 31 March, 2010, Dover, Strafford County, New Hampshire.” If it’s imaged on line it’s helpful to also include a link to the image. It’s always helpful to include a complete transcript.