(a) Any of the following methods may be used to obtain discovery within the state from a person who is not a party to the action in which the discovery is sought: (1) An oral deposition under Chapter 9 (commencing with Section 2025.010). (2) A written deposition under Chapter 11 (commencing with Section 2028.010). (3) A deposition for production of business records and things under Article 4 (commencing with Section 2020.410) or Article 5 (commencing with Section 2020.510). (b) Except as provided