Perhaps you should try some spelling variations:
dat tren » dat trong, dua tren
dau tren » dau tien, dau tieng, dau trong
sach ky » sac ky, sach y, sach ty
danh vi » hanh vi, dinh vi, danh di
va danh » va dinh, va dan, va hanh
te sach » toc sach
hieu va » hieu qua
nang co » nang cao, nang doc, nang noi
nam xua » nam cua, nam mua, nam qua
xua va » xuat va, vua va, sua va
co loi » co hoi

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach ky nang co loi. ((hieu va) or (lieu va)) nam xua va danh vi ((dau tren) OR (dat tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky nang co loi. ((hieu va) OR (lieu va)) nam xua va danh vi ((dau tren) OR (dat tren)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky nang co loi. ((hieu va) or (lieu va)) nam xua va danh vi ((dau tren) OR (dat tren))".
• Adding a wildcard symbol may retrieve word variants: te sach ky nang co loi. ((hieu va) or (lieu va)) nam xua va danh vi ((dau tren) OR (dat tren))*.