Perhaps you should try some spelling variations:
sach nganh » sach ngan, sach tranh, cac nganh
trinh lap » trinh luat, trinh luan, trinh phap
nganh ky » nganh y, nganh xay, hanh ky
tu sach » thu sach, te sach, tu cach
su sach » vu sach
so sach » so sanh, bo sach, co sach
lap chi » tap chi, la chi, lai 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 nganh ky chi đong luc ) or ( ((su sach) or (so sach)) trinh lap chi đong luc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tu sach nganh ky chi đong luc ) OR ( ((su sach) OR (so sach)) trinh lap chi đong luc )).
• Adding a wildcard symbol may retrieve word variants: (( tu sach nganh ky chi đong luc ) or ( ((su sach) or (so sach)) trinh lap chi đong luc ))*.