| Reference Number | Title | Date | Series |
| RNT/SM/2/1/33 | Triple Bill | 17 June 1968 - 27 July 1968 | Pre-South Bank Show Reports |
| CF/8/7 | A Most Unwarrantable Intrusion (Triple Bill part 2) | 1968 | Scripts |
| RNT/CO/1/31 | Triple Bill (Covent Garden Tragedy, In His Own Write, A Most Unwarrantable Intrusion) | 1968 | Costume Department Production Files |
| RNT/PR/2/1/50 | Triple Bill for the National Theatre, Three one-act comedies, Actors to direct. | 4 April 1968 | Press Releases 1960-1979 |
| RNT/PP/3/9/1/7 | Triple Bill | 1968 | Pre-South Bank Cast Lists |
| RNT/PR/4/1/28 | Triple Bill | October 1967 - August 1968 | Press Production Review Files |
| RNT/PP/1/1/158 | Triple Bill | June 1968 | Pre-South Bank Programmes |
| RNT/SM/1/33 | Triple Bill | 1968 | Prompt Scripts |
| RNT/PP/2/1/32 | Triple Bill | June 1968 | Pre-South Bank Posters |