Since February 2021, P. Le Failler has been collaborating with No. 4 Center of National Archives (located in Dalat). In addition to the woodblock prints used to print the dynastic annals, this archive center, established since 2006, preserves sources relating to the central part of the country, including those of the former High Residency of Annam. As part of a long-standing collaboration between the EFEO and the Vietnamese Archives, it was decided to publish a bilingual guide to the archival collections held at No. 4 Center (similar to the guides to the sources of No. 1 and 3 Centers produced in the past).

 fieldwork