Perhaps you should try some spelling variations:
nam thuc » nam thuoc, am thuc, nam thu
thuc dan » thuc hanh, hoc dan, thuc vat
tvon tai » ton tai, tron tai, thong tai
sang ky » sang kyo, dang ky, tang ky
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
dan ky » van ky
va nam » van nam, ha nam, va nay
cua te » cua tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc ((sang ky) or (dan ky)) nang xa hoi. hieu va nam thuc dan ((von tai) or (tvon tai)) cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc ((sang ky) OR (dan ky)) nang xa hoi. hieu va nam thuc dan ((von tai) OR (tvon tai)) cua te.
• Adding a wildcard symbol may retrieve word variants: toc ((sang ky) or (dan ky)) nang xa hoi. hieu va nam thuc dan ((von tai) or (tvon tai)) cua te*.