Parties may obtain discovery by one or more of the following methods: depositions upon oral examination or written questions; written interrogatories; production of documents or things or permission to enter upon land or other property, for inspection and other purposes; physical and mental examinations, including additional medical opinions under Article 1464; request for release of medical records; and requests for admission. Unless the court orders otherwise under Article 1426, the frequency of use of these methods is not limited.