Columbia subject headings:
Harvard subject headings:
Architecture--Germany--Frankfurt am Main--21st century.
Frankfurt am Main (Germany)--Buildings, structures, etc.--Pictorial works.
Mäckler, Christian, 1951-
Office buildings--Germany--Frakfurt am main.
OpernTurm (Frankfurt am Main, Germany)--Pictorial works.
Tall buildings--Germany--Frankfurt am Main.
Princeton subject headings:
Architecture--Germany--Frankfurt am Main--21st century.
Mäckler, Christoph, 1951-
Office buildings--Germany--Frakfurt am main.
Tall buildings--Germany--Frankfurt am Main.