You can 'OR-ing' your query wrapping strings in parenthesis and using the symbol ||

EXAMPLE: ((brand new car) || (old airplanes))
Finds all articles containing the string 'brand new car' or 'old airplanes'

You can 'AND-ing' your query wrapping strings in parenthesis and using the symbol &&

EXAMPLE: ((brand new car) && (old airplanes))
Finds all articles containing the string 'brand new car' and the string 'old airplanes'

Basically you can use any regular expressions, just experiment a bit :-)