Perhaps you should try some spelling variations:
sach nganh » sach ngan, sach tranh, cac nganh
nganh cong » nhanh chong, thanh cong
cong thai » cong hai, hong thai, cong thanh
trinh co » trinh cong, trinh hoa, trinh ky
trinh do » trinh ky
te sach » toc sach
tu sach » thu sach, su sach, tu cach

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( te sach ((trinh co) OR (trinh do)) khi đong luc ) or ( tu sach nganh cong thai đong luc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( te sach ((trinh co) OR (trinh do)) khi đong luc ) OR ( tu sach nganh cong thai đong luc )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( te sach ((trinh co) OR (trinh do)) khi đong luc ) or ( tu sach nganh cong thai đong luc ))".
• Adding a wildcard symbol may retrieve word variants: (( te sach ((trinh co) OR (trinh do)) khi đong luc ) or ( tu sach nganh cong thai đong luc ))*.