I recently did an experiment testing photosynthesis in soybean plants after simulated acid rain. We had three treatments one was a control which recieved no acid solution, a soil pH treatment in which the acidic solution was only added to the soil and a foliar pH treatment in which, only the leaves were sprayed with an acidic solution. We then are going to see which treatment had a greater effect. For my report I need to find three journal articles (primary literatue) that are relevant to the experiment and I am having some trouble finding anything of use to me. I was wondering if someone could help me find some articles.