A preliminary list of some sources I have been looking at:
1) "Foreign Labour Migration and the Economic Crisis in the EU: Ongoing and Remaining Issues of the Migrant Workforce in Germany," Anna Mhyngee Kim (http://ftp.iza.org/dp5134.pdf)
2) "Wage and Employment Effects of Immigration to Germany: Evidence from a Skill Group Approach," Holger Bonin (http://ftp.iza.org/dp1875.pdf)
3) "Turkish Labour Migration to Germany: Impact on Both Economies," Gottfried E. Volker (http://www.jstor.org/stable/4282582?seq=1#page_scan_tab_contents)
4) "The Impact of Immigration on Germany’s Society" (http://ec.europa.eu/dgs/home-affairs/what-we-do/networks/european_migration_network/reports/docs/emn-studies/illegally-resident/de-finalstudy-eng_en.pdf)
5) "A Comparative Study of Net Transfers for Different Immigrant Groups: Evidence from Germany," Christer Gerdes (http://onlinelibrary.wiley.com/doi/10.1111/j.1468-2435.2009.00573.x/epdf)
6) "Economic Impacts of Immigration: A Survey," Sari Pekkala Kerr & William R. Kerr (http://www.hbs.edu/faculty/Publication%20Files/09-013_15702a45-fbc3-44d7-be52-477123ee58d0.pdf)
7) " From Gastarbeiter to “Ausländische Mitbürger”: Postnational Citizenship and In-Between Identities in Berlin," Fayzi Baban (http://www.tandfonline.com/doi/pdf/10.1080/13621020600633119)
8) "Unsung Heroes," Deborah Steinborn (http://wpj.sagepub.com/content/28/4/100.full.pdf+html)
9) "Survey: Which Turkey," The Economist (http://search.proquest.com/docview/224005916?accountid=14784)
10) Arab America: Gender, Cultural Politics, and Activism, Nadine Naber
11) "Identity and Poststructural Theory in SLA," Bonny Norton
1) "Foreign Labour Migration and the Economic Crisis in the EU: Ongoing and Remaining Issues of the Migrant Workforce in Germany," Anna Mhyngee Kim (http://ftp.iza.org/dp5134.pdf)
2) "Wage and Employment Effects of Immigration to Germany: Evidence from a Skill Group Approach," Holger Bonin (http://ftp.iza.org/dp1875.pdf)
3) "Turkish Labour Migration to Germany: Impact on Both Economies," Gottfried E. Volker (http://www.jstor.org/stable/4282582?seq=1#page_scan_tab_contents)
4) "The Impact of Immigration on Germany’s Society" (http://ec.europa.eu/dgs/home-affairs/what-we-do/networks/european_migration_network/reports/docs/emn-studies/illegally-resident/de-finalstudy-eng_en.pdf)
5) "A Comparative Study of Net Transfers for Different Immigrant Groups: Evidence from Germany," Christer Gerdes (http://onlinelibrary.wiley.com/doi/10.1111/j.1468-2435.2009.00573.x/epdf)
6) "Economic Impacts of Immigration: A Survey," Sari Pekkala Kerr & William R. Kerr (http://www.hbs.edu/faculty/Publication%20Files/09-013_15702a45-fbc3-44d7-be52-477123ee58d0.pdf)
7) " From Gastarbeiter to “Ausländische Mitbürger”: Postnational Citizenship and In-Between Identities in Berlin," Fayzi Baban (http://www.tandfonline.com/doi/pdf/10.1080/13621020600633119)
8) "Unsung Heroes," Deborah Steinborn (http://wpj.sagepub.com/content/28/4/100.full.pdf+html)
9) "Survey: Which Turkey," The Economist (http://search.proquest.com/docview/224005916?accountid=14784)
10) Arab America: Gender, Cultural Politics, and Activism, Nadine Naber
11) "Identity and Poststructural Theory in SLA," Bonny Norton