ProQuest Science and Technology lets you search the following ProQuest resources with one search box:
Advanced Technologies & Aerospace Collection;
Agricultural Science Collection
Aquatic Science Collection;
Atmospheric Science Collection;
Biological Science Collection;
Computer Science Collection;
Earth Science Collection;
Engineering Collection;
Environmental Science Collection;
Illustrata: Natural Sciences;
Illustrata: Technology;
Materials Science Collection;
Dissertations & Theses: UK & Ireland: Science & Technology;
Dissertations & Theses A&I: Science & Technology.