A copy of your vehicle's smog certificate (also known as the Vehicle Inspection Report) can be obtained only from the smog station which inspected your vehicle; and might require a service fee. In most instances the smog testing center will provide a duplicate free of charge. Contact the smog station where your vehicle was inspected.
In terms of "smog check results"... that information is kept in electronic format in the VID (Vehicle Information Database) which is run by the State of California Bureau of Automotive Repairs, and looked over by the California Air Resources Board.
Once a vehicle receives an official smog check (as opposed to a smog check pre-test) the smog inspection data, including pass or fail results, are stored with the State and available to government entities, such as the California DMV, indefinitely. For vehicle registration purposes, the DMV in most circumstances will not require a hard-copy of your vehicle's smog check results, smog certificate or VIR.
