So I'm in I Corinthians and read this: Περὶ δὲ τῶν πνευματικῶν, ἀδελφοί, οὐ θέλω ὑμᾶς ἀγνοεῖν
Περὶ δὲ τῶν πνευματικῶν  But (or, now) concerning the spiritual (what?  persons? things?)
so I wanted to search I Corinthians for other times Paul used τῶν πνευματικῶν (the spiritual).  But I would want this in all cases.  This is the genitive.  I want nominative, accusative, and dative.   Other places where Paul talks about this.  
If I search for the phrase, I only get the exact phrase and not the others.
Just like when I click on one word and have the lemma as an option, I need more options in a phrase search.  
Yes, I did a search on just the adjective πνευματικός and found ὁ δὲ πνευματικὸς and τὰ πνευματικὰ, but what if I had a more complex phrase over more than just i Corinthians.  
The point is that this needs more thought and work.
I hope I made this clear
thank you