To murge multiple assemblys into one you can use Fody/Costura. It allows you to merge multiple assemblys into 1 project. In your main project you add it(can be done via nuget). Then just in weavers.xml (file that will be automaticly generated add these text:
<Costura>
<IncludeAssemblies>
Project.MyData.Dutch
Project.MyData.French
Project.MyData.English
</IncludeAssemblies>
</Costura>
(it should be the same name as the reference, so without the .dll suffix)