Perhaps you should try some spelling variations:
"think liquid chromatography" » "thin liquid chromatography", "tank liquid chromatography", "third liquid chromatography"
"thick layer chromatography" » "thick layers chromatography", "thick bilayer chromatography", "thin layer chromatography"
"think gas chromatography" » "thin gas chromatography", "think fast chromatography", "think case chromatography"

Try widening your search to All Fields.

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: (((("thick layer chromatography") OR ("think gas chromatography"))) OR ("think liquid chromatography")).
• Removing quotes may allow a broader search: (((( thick layer chromatography ) or ( think gas chromatography ))) or ( think liquid chromatography )).
• Adding a wildcard symbol may retrieve word variants: (((("thick layer chromatography") or ("think gas chromatography"))) or ("think liquid chromatography"))*.