Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
nam thuc » nam thuoc, am thuc, nam thu
tu sach » thu sach, su sach, te sach
sach ly » sach y, sach lo, sach ty
ly nang » ky nang, ly hang, ly vang
mai hoi » mai khoi, dai hoi, lai hoi
thuc va » thuc vat, thuc dan, thuc day
va hang » van hang, va nang, va lang
hang di » hang doi, hang vi, hang dien
di cua » dai cua, doi cua, de cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ly nang ((xa hoi) or (mai hoi)). hieu van nam thuc va hang di cua vat~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ly nang ((xa hoi) OR (mai hoi)). hieu van nam thuc va hang di cua vat.
• Adding a wildcard symbol may retrieve word variants: tu sach ly nang ((xa hoi) or (mai hoi)). hieu van nam thuc va hang di cua vat*.