Perhaps you should try some spelling variations:
peptide chromatography » preparative chromatography, liquid chromatography, paper chromatography
fluid chromatography » liquid chromatography, liquid chromatographic, layer chromatography
link gas » link goes, link a, link ads

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: (( link gas chromatography ) OR ( think ((peptide chromatography) OR (fluid chromatography)) ))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( link gas chromatography ) or ( think ((peptide chromatography) OR (fluid chromatography)) ))*".