How can I combine this code into one or two LINQ queries?

Question

I'm perhaps being a bit lazy asking this here, but I'm just getting started with LINQ and I have a function that I am sure can be turned into two LINQ queries (or one nested query) rather than a LINQ and a couple of foreach statements. Any LINQ gurus care to refactor this one for me as an example?

The function itself loops through a list of .csproj files and pulls out the paths of all the .cs files included in the project:

static IEnumerable<string> FindFiles(IEnumerable<string> projectPaths)
{            
    string xmlNamespace = "{http://schemas.microsoft.com/developer/msbuild/2003}";
    foreach (string projectPath in projectPaths)
    {
        XDocument projectXml = XDocument.Load(projectPath);
        string projectDir = Path.GetDirectoryName(projectPath);

        var csharpFiles = from c in projectXml.Descendants(xmlNamespace + "Compile")
                              where c.Attribute("Include").Value.EndsWith(".cs")
                              select Path.Combine(projectDir, c.Attribute("Include").Value);
        foreach (string s in csharpFiles)
        {
            yield return s;
        }
    }
}

Answer 1

How about:

        const string xmlNamespace = "{http://schemas.microsoft.com/developer/msbuild/2003}";

        return  from projectPath in projectPaths
                let xml = XDocument.Load(projectPath)
                let dir = Path.GetDirectoryName(projectPath)
                from c in xml.Descendants(xmlNamespace + "Compile")
                where c.Attribute("Include").Value.EndsWith(".cs")
                select Path.Combine(dir, c.Attribute("Include").Value);