Perhaps you should try some spelling variations:
dua tren » dung tren
danh doi » danh di, thanh doi, dung doi
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
va danh » va dinh, va dan, va hanh
cuu tre » cua tre, cau tren, cau treo
hieu ve » hieu va, hieu van
cac tu » cac thu, cach tu, cac du
ma hoi » mai hoi, xa hoi, me hoi
ve cac » va cac, vien cac

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 ky nang ((ma hoi) or (ma hoa)). hieu ve cac tu va danh doi ((dua tren) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky nang ((ma hoi) OR (ma hoa)). hieu ve cac tu va danh doi ((dua tren) OR (cuu tre)).
• Adding a wildcard symbol may retrieve word variants: su sach ky nang ((ma hoi) or (ma hoa)). hieu ve cac tu va danh doi ((dua tren) or (cuu tre))*.