Perhaps you should try some spelling variations:
trinh vat » trinh van, trinh luat, sinh vat
sach thu » sach thue, sach thieu, sach tham
thu nang » thi nang, thu hang, thu bang
tu sach » thu sach, su sach, te sach
hieu va » lieu va, hieu qua
va pham » van pham, va phat, va phap
tinh vi » trinh vi, tinh voi, tinh va
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 thu nang ((x hoi) or (x ho)). hieu va pham duc va ((tinh vi) or (trinh vat)) luu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach thu nang ((x hoi) OR (x ho)). hieu va pham duc va ((tinh vi) OR (trinh vat)) luu tre.
• Adding a wildcard symbol may retrieve word variants: tu sach thu nang ((x hoi) or (x ho)). hieu va pham duc va ((tinh vi) or (trinh vat)) luu tre*.