Build up of 12. Armee in Bulgaria, 1940-1941

[LB]

Hello Feldgrauians !

I'm looking for a schedule of the build-up of 12. Armee in Bulgaria prior to "Marita".
When was it activated as the leading HQ for the operation ?
When were its first combat, combat support and combat services support units deployed in Bulgaria (especially division-sized ones) ?
Where were they deployed in Bulgaria (I heard of several bridgeheads across the Danube river) ?

Thanks for your help !
Regards,

CNE503