Intersection returns strings contained in boths given slices.

RemoveEach returns a new slice with elements not contained in a drop list.

StringSliceContains returns true, if a given string is contained in a slice.

Truncate truncates a string.

UnescapeTrim unescapes HTML character references and trims the space of a given string.

ISBNPattern to match ISBN.

ISSNPattern is a regular expression matching standard ISSN.