Currently, I am working on the integration process of immigrants into German labor market. I consider different migrant cohorts: muslim, balkan, East EU and West EU considering their migration type (refugee/economic/family) and year of arrival (1980s/1990s/2000/during migration crisis). My main concern is the failure integration of some cohorts (e.g. Muslim). There are two main arguments provided in public and academia to answer that failure. One states that it is mainly because of their cultural differences and they stick to their cultural norms, traditions and origin identity therefore it makes significant barriers to their integration process. This idea usually has been supported by right wing politics and nationalist populists. The opposite attitude highlight the economic discrimination against some specific group of immigrants who are culturally more different than natives.
I would be so happy if you introduce me some highly cited studies related to the described discussion.