my( $authors, $title, $thing, $pub, $date, $comment, $no ) = m/ ^ ## Author(s): Capture the minimum needed to satisfy that: ## a) It ends with a '. ' ## b) And the next word is not an initial ## IE: Lookahead and check the next word starts with ## 1 uppercase *and* one lowercase character. -( .*? \. ) \s(?=[A-Z][a-z]) ## Title: Greedily capture something that ends with '. ' ( .+ ) \.\s+ ## Location: Non-greedily capture ## Ends with a ': '. ## Doesn't contain a ':' ( [^:]+? ) : \s+ ## Publisher: ## Single word followed by a ', ' (\S+), \s+ ## Year: Capture Four digits ## Discard anything else upto '. ' ( \d{4} ) [^.]* \. \s+ ## Comment: Greedy capture non-'[' characters ## Ie. Stop capturing when you see a '[' ( [^\[]+ ) ## No: Capture 1 (or more) digits between '[' & ']' ## Discard any trailing space to the EOS. \[ ( \d+ ) \] \s* $ /x;