Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
sach thu » sach thue, sach thieu, sach tham
dau truc » cau truc, dai truc, doan truc
truc van » truc va, thuc van, truc ban
su sach » so sach, vu sach
nang xa » lang xa, nang ma, mang xa
cua tre » cuu tre, cua triet, dua tren
hanh di » hanh vi, hanh de, hang di
va dau » va dao
cua te » cua tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach thu ((nang xa) or (nang x)) hoi. lieu va dau truc van hanh di ((cua tre) OR (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach thu ((nang xa) OR (nang x)) hoi. lieu va dau truc van hanh di ((cua tre) OR (cua te))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach thu ((nang xa) or (nang x)) hoi. lieu va dau truc van hanh di ((cua tre) OR (cua te))*".