|9.2.1984-16.3.1989||Mayor||West Berlin/City Administration|
|10.11.1989||52922||Telegram||International perceptions of the German reunification (1989–1990)|
Description of a “historic night” of free travel between East and West Berlin.
|14.11.1989||52958||Telegram||International perceptions of the German reunification (1989–1990)|
Report on the events that unfolded on and after 9.11.1989. Van der Tas is critical of the "false note", the claim for reunification, brought into the festivities by FRG Chancellor Kohl.