Is this a quantitative or qualitative study?

Please answer the following questions related to the corresponding article each question set per article an average of 400 words. Nachreiner, N., Dagher, R., McGovern, P., Baker, B., Alexander, B., & Gerberich, S. 2007. Successful return to work for cancer survivors. AAOHN Journal, 55(7), 290-295. Is this a quantitative or qualitative study? Why? What is the study design? What are possible problems or risks to conclusions in using this study design? Is triangulation present? This was presented in reference to qualitative research but can it also be used in quantitative research? Does the study identify a causal relationship? If so, between which variables? What are the limitations of this study? Blumberg, S.J. J.V. Luke, & M.L. Cynamon. 2006. Telephone coverage and health survey estimates: evaluating the need for concern about wireless substitution. American Journal of Public Health, 96 (5), 926-931 What was the research question in this study? (Is there sampling bias?) What was the unit of analysis? Sampling units? What were the main results of this study? What were the policy implications? What were some limitations of the study? Stern, M. J., Smyth, J. D., & Mendez, J. (2012). The effects of item saliency and question design on measurement error in a self-administered survey. Field Methods, 24(1), 3-27 Describe the sampling plan. What is the theory underlying the research? What is the mode of administration? Advantages/disadvantages? What is satisficing? What were the main results/conclusions of the study? Dagher, R., McGovern, P., & Dowd, B., & Gjerdingen, D. 2012. Postpartum depression and health services expenditures among employed women. Journal of Occupational and Environmental Medicine,54(2), 210-215. In the literature review portion of the article an Australian study is mentioned. What prevented that study from drawing a stronger conclusion about the effects of postpartum depression? What was the problem with the expenditure data the investigators had to account for in order to perform the regression? How was this problem handled? What effect did selection bias have on the conclusions drawn in this study?