Letter from an online museum or archival collection
Format: Author, A. A., Authorb, B. B., Authorc, C. C., & Authord, D. D. (YYYY). [Description of letter]. Name of collection, Repository, museum or owner, Museum Location. URL
Kanjeng Kyai Angrurah Jambe of Badung & Kyai Angrurah Agung of Mengwi. (1768). [Letter in Balinese on a sheet of gold]. British Library Digitised Manuscripts (Egerton MS 765). http://www.bl.uk/manuscripts/FullDisplay.aspx?ref=Egerton_MS_765
In-text: (Kanjeng Kyai Angrurah Jambe of Badung & Kyai Angrurah Agung of Mengwi, 1768).