The resource files appear under Customers.cs. Customers.resx is the resource file for the default culture, which is built into the main assembly. Resource files for other locales include a language code, and, optionally, a country code. Language and country codes are specified in ISO-639 and ISO-3166, respectively.
For example, Customers.ch-CHS.resx is the resource file for Chinese as spoken in Chinese (Simplified).