even more reference citations

Write the correct references citations in the body of the text for the following

...evidence which supports their theory (Decker and brown, in 2005, Decker and brown in 2007, Decker and brown again in 2007. Collins and Pine in 2009. VanVeen and Thomson in 2009. Drumhold, ebert, Norris and Smirh, in 2007, 2008, 2008, 2008)

This makes no sense to me.