Perhaps you should try some spelling variations:
cap nuoc » dat nuoc
cac nuoc » hoc nuoc, dat nuoc, cua nuoc
sach ky » sac ky, sach y, sach ty
lap cua » lai cua, tap cua, lam cua
su sach » so sach, vu sach
hieu ve » hieu va, hieu van
tang xa » trang xa, tang ma, lang xa
ky tang » ky nang, ky dang, kho tang
lap ca » lap va, lap da, lap xa

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 tang xa hoi. hieu ve ((cac nuoc) or (cap nuoc)) may tinh ((lap ca) OR (lap cua)) viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky tang xa hoi. hieu ve ((cac nuoc) OR (cap nuoc)) may tinh ((lap ca) OR (lap cua)) viet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky tang xa hoi. hieu ve ((cac nuoc) or (cap nuoc)) may tinh ((lap ca) OR (lap cua)) viet*".