Perhaps you should try some spelling variations:
cac thuc » cach thuc, cac thu, can thuc
hieu va » lieu va, hieu qua
cua tre » cuu tre, cua triet, dua tren
va hanh » van hanh, va thanh, va danh
thuc va » thuc vat, thuc dan, thuc day
vu sach » vu bach, vu khach
lang ha » long ha
ky lang » ky nang, ky dang, ky tang
su sach » so sach
ha hoi » hoa hoi, ha noi, xa hoi
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: ((vu sach) or (su sach)) ky lang ha hoi. hieu va cac thuc va hanh vi ((cua tre) OR (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((vu sach) OR (su sach)) ky lang ha hoi. hieu va cac thuc va hanh vi ((cua tre) OR (cua te)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((vu sach) or (su sach)) ky lang ha hoi. hieu va cac thuc va hanh vi ((cua tre) OR (cua te))".
• Adding a wildcard symbol may retrieve word variants: ((vu sach) or (su sach)) ky lang ha hoi. hieu va cac thuc va hanh vi ((cua tre) OR (cua te))*.