Perhaps you should try some spelling variations:
sach thue » sach thu, sach thieu, sach tham
thue nang » thien nang, thuat nang, thi nang
trinh vi » trinh va, trinh ve, trinh viet
tu sach » thu sach, su sach, te sach
hieu va » lieu va, hieu qua
va pham » van pham, va phat, va phap
tinh vi » tinh voi, tinh va, dinh vi
luu tre » luu tru, cuu tre, luy tre
x hoi » xa hoi, o hoi, 5 hoi

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 thue nang ((x hoi) or (x ho)). hieu va pham duc va ((tinh vi) or (trinh vi)) luu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach thue nang ((x hoi) OR (x ho)). hieu va pham duc va ((tinh vi) OR (trinh vi)) luu tre.
• Adding a wildcard symbol may retrieve word variants: tu sach thue nang ((x hoi) or (x ho)). hieu va pham duc va ((tinh vi) or (trinh vi)) luu tre*.