Out of state craft fair sales

I am a California resident and sold some art work at a 2 day craft fair in Oregon and a 2 day craft fair in Pennsylvania.

 

I paid sales tax to Pennsylvania on my craft fair sales. Oregon does not have a sales tax. I am reporting the income from my Oregon and Pennsylvania craft sales on my Federal and California State income tax returns.

 

Do I also file separate state income tax forms with Oregon and Pennsylvania on my sales (in addition to reporting that out of state income on my California tax return)? If yes, can I avoid double taxation on the same sales (e.g., paying CA and PA income tax on the same sales)?