Sumerian Primary Sources?

[JessieD]

Can anyone recommend some good Sumerian Primary Sources? Or, even secondary sources? I have a few books, but I'm looking for more. I'll list what primary and secondary sources are, in case someone is unaware.

Primary Source - Material produced by a person or a group directly involved with event or topic either as participants or witnesses. Examples: Birth certificate, hi res photos of Egyptian Hieroglyphics at Giza, official documents, letters from person of interest, autobiographies, etc.

Secondary Source - Books and articles in scholarly journals that comment and interpret primary sources. Examples: Biographies, a documentary, propaganda (though this could also be primary), papers in journals, modern books written about older topics...