How to I calculate "Inc subj to tax by oth st" on AZ Form 309?

I'm a resident of CA, I worked in AZ for a few weeks and got a W-2. Now I'm filling out state tax returns in TurboTax and it says "Check This Entry   Form 309 (California): Inc subj to tax by oth st must be entered.  Inc subj to tax by oth st."  I don't know what it's asking for.