I put in "harpo" and "groucho" and got this:

- harpo
- groucho
- chico
- zeppo
- groucho†
- marx brothers
- gummo
- dracula 1931
- marx, chico
- brothers
- marx
- casablanca
- margaret dumont
- marx, harpo

All of those make some sense, except dracula and casablanca.