The search is based on Perl-compatible, case-insensitive regular expressions. Thus:
.*(a dot and a star, no spaces between and at either end) in the search field between your words
\d means [0-9],
\s - whitespace,
\b - word border.
More details on Perl pages.
Patterns matching any word (such as
.*, all periods etc.) are forbidden.
The expression should be at least two characters long.