This resource has its own search interface, but is also searchable under the ICTRP search portal.
The register contains over 14,000 studies (April 2023).
The English language introduction leads into a German and English search interface.
Default operator AND
Boolean operators AND, OR. Words can be excluded by prefixing with a minus sign (e.g. -cancer)
Phrase searching The help pages say that this does not work yet (13 April 2023)
Nesting Unclear
Truncation * (can be applied at the beginning or end of a word)
Field tags Fielded searching is available via the Extended Search.
Hyphens Hyphens are treated as a space
Help pages Yes
Example breast AND cancer
Saved searches No
Export tagged No
Updated 13 April 2023