Perhaps you should try some spelling variations:
computer cases » computer case (Expand Search), computer classes (Expand Search), computer caries (Expand Search)
del computer » dal computer (Expand Search), delta computer (Expand Search), model computer (Expand Search)
natl comp » al comp (Expand Search), natalia comp (Expand Search)
dna clamp » a clamp (Expand Search)
cases now » cases new (Expand Search), cases non (Expand Search), case now (Expand Search)
comp can » camp can (Expand Search), chimp can (Expand Search), clamp can (Expand Search)
clamp m » clamp _ (Expand Search), clamp j (Expand Search), clamp a (Expand Search)
m newts » _ newts (Expand Search), m news (Expand Search), m newton (Expand Search)
j natl » j nail (Expand Search), _ natl (Expand Search), j nat (Expand Search)
j dna » _ dna (Expand Search), a dna (Expand Search), 1 dna (Expand Search)

You can also try:

• Europeana
• Digital Public Library of America
• CORE

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (((( j natl comp can new ) or ( j dna clamp m newts ))) or ( y del computer cases now ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((( j natl comp can new ) OR ( j dna clamp m newts ))) OR ( y del computer cases now )).
• Adding a wildcard symbol may retrieve word variants: (((( j natl comp can new ) or ( j dna clamp m newts ))) or ( y del computer cases now ))*.