Here are the literature references for the papers cited in the previous passage, as they would appear in the Literature Cited section of Southwestern Naturalist: Fierke, M. K. and J. B. Kauffman. 2005. Structural dynamics of riparian forests along a black cottonwood successional gradient. Forest Ecology and Management 215:149-62. Foster, R. D. and P. R. Wetzel. 2005. Invading monotypic stands of Phalaris arundinacea: a test of fire, herbicide, and woody and herbaceous native plant groups. Restoration Ecology 13:318-24. Galatowitsch, S. M., N. O. Anderson and P. D. Ascher. 1999. Invasiveness in wetland plants in temperate North America. Wetlands 19:733-55. Hovick, S. M. and J. A. Reinartz. 2007. Restoring forest in wetlands dominated by reed canarygrass: the effects of pre-planting treatments on early survival of planted stock. Wetlands 27:24-39. Jenkins, N. J., J. A. Yeakley and E. M. Stewart. 2008. First-year responses to managed flooding of Lower Columbia River bottomland vegetation dominated by Phalaris arundinacea. Wetlands 28: 1018-27. Knutson, M. G., L. E. McColl and S. A. Suarez. 2005. Breeding bird assemblages associated with stages of forest succession in large river floodplains. Natural Areas Journal 25:55-70. Lavergne, S. and J. Molofsky. 2004. Reed canary grass (Phalaris arundinacea) as a biological model in the study of plant invasions. Critical Reviews in Plant Sciences 23:415-29. Zedler, J. B. and S. Kercher. 2004. Causes and consequences of invasive plants in wetlands: opportunities, opportunists, and outcomes. Critical Reviews in Plant Sciences 23:431-52. Based on the article titles and journal names, which of these do you think are primary research articles? Choose as manv as apolv..