Perhaps you should try some spelling variations:
dieu kien » dieu khien, dien bien
kien dat » kien dai, mien dat, tien dat
dat ngoc » dat nuoc, dau ngoc, dang ngoc
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
ky lang » ky nang, ky dang, ky tang
lang xa » lang ha, dang xay, lang van
ngoc va » nuoc va, ngoc ha, goc va
va danh » va dinh, va dan, va hanh
di cau » diem cau
da cau » dat cau, va cau

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. dieu kien dat ngoc va danh ((di cau) or (da cau)) tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky lang xa hoi. dieu kien dat ngoc va danh ((di cau) OR (da cau)) tren.
• Adding a wildcard symbol may retrieve word variants: su sach ky lang xa hoi. dieu kien dat ngoc va danh ((di cau) or (da cau)) tren*.