Horowitz, B. The Hard Thing About Hard Things. Harper Business.
Lua i Stíl Chicago (17ú heag.)Horowitz, Ben. The Hard Thing About Hard Things. Harper Business.
Lua MLA (9ú heag.)Horowitz, Ben. The Hard Thing About Hard Things. Harper Business.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.