Talvez deva tentar algumas variações de ortografia:
nat compr » la compr (Expandir a Pesquisa)
compr can » comp can (Expandir a Pesquisa), computer can (Expandir a Pesquisa), compared can (Expandir a Pesquisa)
nat clamp » dnan clamp (Expandir a Pesquisa), rnap clamp (Expandir a Pesquisa), a clamp (Expandir a Pesquisa)
clamp can » clamp ar (Expandir a Pesquisa), clamp cum (Expandir a Pesquisa), clamp jaw (Expandir a Pesquisa)
dna clamp » a clamp (Expandir a Pesquisa)
can netw » can new (Expandir a Pesquisa), can net (Expandir a Pesquisa), can newts (Expandir a Pesquisa)
clamp a » clamp _ (Expandir a Pesquisa), clamp j (Expandir a Pesquisa)
a netw » a neto (Expandir a Pesquisa), a neta (Expandir a Pesquisa), a netb (Expandir a Pesquisa)
e nat » e nata (Expandir a Pesquisa), e nao (Expandir a Pesquisa), e nas (Expandir a Pesquisa)
_ nat » _ net (Expandir a Pesquisa), _ nad (Expandir a Pesquisa), _ nab (Expandir a Pesquisa)

You can also try:

• Europeana
• Digital Public Library of America
• CORE

Pode obter mais resultados ajustando a pesquisa.

• Se retirar as aspas poderá fazer uma pesquisa mais abragente: (( e nat compr can netw ) or ((( _ nat clamp can netw ) or ( _ dna clamp a netw )))).