I have a simple lambda expression that goes something like this:
x=> x.Lists.Include(l => l.Title).Where(l=>l.Title != String.Empty)
You can include it in the same where statement with the && operator...
x=> x.Lists.Include(l => l.Title).Where(l=>l.Title != String.Empty
&& l.InternalName != String.Empty)
You can use any of the comparison operators (think of it like doing an if statement) such as...
List nums = new List();
nums.Add(3);
nums.Add(10);
nums.Add(5);
var results = nums.Where(x => x == 3 || x == 10);
...would bring back 3 and 10.