Perhaps you should try some spelling variations:
nam thuc » nam thuoc, am thuc, nam thu
vat hanh » vat thanh, van hanh, va hanh
su sach » so sach
vu sach » vu bach, vu khach
hieu ve » hieu va, hieu van
y nang » ky nang, ly nang, v nang
ve nam » he nam, va nam, le nam
di cua » doi cua, de cua, do cua
x hoi » xa hoi, o hoi, x ho

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((su sach) or (vu sach)) y nang x hoi. hieu ve nam thuc vat hanh ((di cua) OR (dai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (vu sach)) y nang x hoi. hieu ve nam thuc vat hanh ((di cua) OR (dai cua)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) or (vu sach)) y nang x hoi. hieu ve nam thuc vat hanh ((di cua) OR (dai cua)) tre".
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (vu sach)) y nang x hoi. hieu ve nam thuc vat hanh ((di cua) OR (dai cua)) tre*.