Perhaps you should try some spelling variations:
sach ngan » sach ngon, sach nha, sach han
trinh lam » trinh lap, trinh tam, trinh cam
tu sach » thu sach, te sach, tu cach
ngan ky » nganh ky, nhan ky, ngan hay
su sach » vu sach
so sach » so sanh, bo sach, co sach
lam chi » nam chi, lam chu, la chi
ky chi » ky thi, ly chi, ke chi

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( tu sach ngan ky chi đong luc ) or ( ((su sach) or (so sach)) trinh lam chi đong luc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tu sach ngan ky chi đong luc ) OR ( ((su sach) OR (so sach)) trinh lam chi đong luc )).
• Adding a wildcard symbol may retrieve word variants: (( tu sach ngan ky chi đong luc ) or ( ((su sach) or (so sach)) trinh lam chi đong luc ))*.