Perhaps you should try some spelling variations:
sach nhah » sach nha, cach nhanh, sach tham
nganh ky » nganh y, nganh xay, hanh ky
thu sach » thuat sach, thuoc sach, thu hoach
tu sach » te sach, tu cach, vu sach
su sach » so sach, vu sach
ky chi » ky thi, ly chi, ke chi
y khi » ly khi, ky khi, my khi

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) OR (su sach)) nganh ky chi đong luc ) or ( thu sach nhah y khi đong luc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( ((tu sach) OR (su sach)) nganh ky chi đong luc ) OR ( thu sach nhah y khi đong luc )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( ((tu sach) OR (su sach)) nganh ky chi đong luc ) or ( thu sach nhah y khi đong luc ))".
• Adding a wildcard symbol may retrieve word variants: (( ((tu sach) OR (su sach)) nganh ky chi đong luc ) or ( thu sach nhah y khi đong luc ))*.