The Serbian Military Archive in Belgrade has a lot of very exciting documents (I have gathered some of the references on aviation bombs that can be found tehre and I'd love to get a copy of them) - but it is not digital and physical access to is more than limited for a non Serbian citizen - I thought of going and visit it but have renounced.
For info these are the rules of access for foreign citizens - quite siliar to the ones in teh former Soviet Union at its worst times:
"The military Archive is not authorized to have a direct communication with foreign legal and physical entities.
Foreign citizens, who would like to use the archival materials of the Military Archive, submit an application to the Diplomatic and Consular Office of the Republic of Serbia in their country or their Diplomatic and Consular Office in the Republic of Serbia.
The received application is submitted to the Office of the Minister of Defense for approval.
When a foreign researcher visits a scientific institution of the Republic of Serbia and submits an application to that institution or directly to the Military Archives, his application with the opinion will be submitted to the Cabinet of the Minister of Defense.
If a foreign researcher does not speak Serbian language, he/she should provide a translator.
etc...etc...
Here's the link to their home page:
Војни архив је установа заштите архивске грађе и документарног материјала који настају у раду Министарства одбране и Војске Србије, или се код њих налази, обавља архивску делатност за потребе органа управе надлежног за одбрану.
www.vojniarhiv.mod.gov.rs
