Fertilizer and other agricultural waste pouring into the Gulf of Mexico creates a larger and larger patch of lifeless ocean each year. Finally, the EPA has a plan of attack. Is it enough?
The abbreviation et al. means and others. It is most often used when a work you are citing in your paper has multiple authors. When a work has two authors, cite both names every time the reference occurs in the text.
English - US. If pushed, I would put the 's with Johann: Johann's et al. findings. I would not attach it to et al., because al. is the abbreviation of a Latin word, and Latin doesn't form the possessive by 's. I would far prefer to get around the question by writing: the findings of Jahann et al. Dec 1, 2009.