Kriegel Robert. (1991). If it Ain't Broke-- Break it!: And other unconventional wisdom for a changing business world. Warner Books a time warner company.
Lua i Stíl Chicago (17ú heag.)Kriegel Robert. If It Ain't Broke-- Break It!: And Other Unconventional Wisdom for a Changing Business World. USA: Warner Books a time warner company, 1991.
Lua MLA (9ú heag.)Kriegel Robert. If It Ain't Broke-- Break It!: And Other Unconventional Wisdom for a Changing Business World. Warner Books a time warner company, 1991.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.