Perhaps you should try some spelling variations:
"thin layer chromatography" » "thin gas chromatography"
"than layer chromatography" » "than gas chromatography", "than later chromatography", "than laser chromatography", "than larger 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: (((("thin layer chromatography") OR ("thin liquid chromatography"))) OR ("than layer chromatography")).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"thin layer chromatography\") OR (\"thin liquid chromatography\"))) or (\"than layer chromatography\"))".
• Removing quotes may allow a broader search: (((( thin layer chromatography ) OR ( thin liquid chromatography ))) or ( than layer chromatography )).
• Adding a wildcard symbol may retrieve word variants: (((("thin layer chromatography") OR ("thin liquid chromatography"))) or ("than layer chromatography"))*.