Perhaps you should try some spelling variations:
hien cach » hien cac, hieu cach, thien hach
hieu hien » bieu hien, dieu hien, chieu chien
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
cua tre » cua te, cua triet, dua tren
doan vi » doan va, don vi, doan thi
cuu tre » cau tren, cau treo
cach tu » cach thuc
lang xa » lang ha, dang xay, lang van
ky lang » ky nang, ky dang, ky tang
dan vi » don vi, dan va, gan vi

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 lang xa hoi. hieu hien cach tu va ((dan vi) or (doan vi)) ((cua tre) OR (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky lang xa hoi. hieu hien cach tu va ((dan vi) OR (doan vi)) ((cua tre) OR (cuu tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky lang xa hoi. hieu hien cach tu va ((dan vi) or (doan vi)) ((cua tre) OR (cuu tre))".
• Adding a wildcard symbol may retrieve word variants: su sach ky lang xa hoi. hieu hien cach tu va ((dan vi) or (doan vi)) ((cua tre) OR (cuu tre))*.