To find both words you are searching for, use a "+."
Example: +Analytical +Services
To find either word you are searching for, type the words normally.
Example: Analytical Services
To find a phrase, enclose the phrase in quotes.
Example: "Analytical Services"
To find the first word and omit the second word, use a "+" for the word you want and a "-" for the word you would like omitted.
Example: +Analytical -Services