Perhaps you should try some spelling variations:
tu nhanh » tu nhan, tu hanh, tu thanh
van hanh » van thanh, ban hanh, van ban
cham luc » cham soc, nhan luc, cham cuu
tu sach » thu sach, su sach, te sach
su cham » su pham, tu cham, vu cham
van anh » van thanh, tuan anh, van minh
hieu su » hieu sau, tieu su, hieu so
sach tu » sach thu, cach tu, sach ty
hoc hoi » hoc khoi, hoc hoa, hoc noi
doc hoi » duoc hoi, doc hai, doi hoi
cua tre » cua te, cuu tre, cua triet
vi cua » vai cua, di cua

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 tu nhanh ((doc hoi) OR (hoc hoi)). hieu su cham luc ((van hanh) or (van anh)) vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach tu nhanh ((doc hoi) OR (hoc hoi)). hieu su cham luc ((van hanh) OR (van anh)) vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach tu nhanh ((doc hoi) OR (hoc hoi)). hieu su cham luc ((van hanh) or (van anh)) vi cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach tu nhanh ((doc hoi) OR (hoc hoi)). hieu su cham luc ((van hanh) or (van anh)) vi cua tre*.