Business & Economics
Green Roof
100%
Prototype
54%
Middle Age
29%
Reinforced Concrete
17%
Vegetation
16%
Engineering Design
15%
Knowledge Gap
12%
Durables
12%
Pioneering
11%
Invention
11%
Traits
9%
Innovation
8%
Germany
7%
Social Sciences
antiquity
28%
modern times
14%
Renaissance
13%
knowledge gap
12%
historical development
11%
invention
11%
building
10%
Federal Republic of Germany
8%
innovation
7%
engineering
6%
lack
5%
time
3%
Earth & Environmental Sciences
roof
50%
Medieval
17%
reinforced concrete
9%
garden
8%
terrace
7%
innovation
6%
Europe
5%
engineering
5%
vegetation
4%
world
4%
material
3%
Engineering & Materials Science
Roofs
53%
Patents and inventions
9%
Reinforced concrete
6%