Perhaps you should try some spelling variations:
hieu sach » chieu sach, hieu cach, dien sach
trinh cua » trinh luat, trinh quan, trinh luan
doc hieu » toc thieu, hoc thieu, hoc hien
tinh cua » sinh cua, tinh chat, tranh cua
cang tac » cong tac, canh tac, can tac
sang tac » sang tao, sang tai, sang than
phat dau » phan dau, pham dau, phap dau

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

• Performing a fuzzy search may retrieve terms with similar spellings: doc hieu sach - nhanh ((tinh cua) OR (trinh cua)) khong ((cang tac) or (sang tac)) phat dau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu sach - nhanh ((tinh cua) OR (trinh cua)) khong ((cang tac) OR (sang tac)) phat dau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc hieu sach - nhanh ((tinh cua) OR (trinh cua)) khong ((cang tac) or (sang tac)) phat dau".
• Adding a wildcard symbol may retrieve word variants: doc hieu sach - nhanh ((tinh cua) OR (trinh cua)) khong ((cang tac) or (sang tac)) phat dau*.