Perhaps you should try some spelling variations:
nam thuc » nam thuoc, am thuc, nam thu
thuc dan » thuc hanh, hoc dan, thuc vat
hoi cua » hoi chuc
vai cua » dai cua, hai cua, lai cua
dan dau » danh dau, doan dau, van dau
toc sac » toc sach, toc san, hoc sach
tay hoi » tay ho, tao hoi, tay thai
xay hoi » xa hoi, cay phoi, gay thoi
ky dang » ky nang, ky danh
hieu va » lieu va, hieu qua
va nam » van nam, ha nam, va nay
sac ky » cac ky, sai ky

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sac ky dang ((xay hoi) or (tay hoi)). hieu va nam thuc dan dau ((vai cua) or (hoi cua)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sac ky dang ((xay hoi) OR (tay hoi)). hieu va nam thuc dan dau ((vai cua) OR (hoi cua)) triet.
• Adding a wildcard symbol may retrieve word variants: toc sac ky dang ((xay hoi) or (tay hoi)). hieu va nam thuc dan dau ((vai cua) or (hoi cua)) triet*.