Perhaps you should try some spelling variations:
van nang » van quang, van ban, van dong
su triet » su viet, su tien, ve triet
van hanh » van thanh, ban hanh, van anh
sach van » sach han, sach va, bach van
truc van » truc va, thuc van, truc ban
su sach » so sach, vu sach
hanh de » hanh ve, hanh kem
cua tu » cua tuc, cua su, cua cu
ve cac » va cac, vien cac
ve cau » ke cau, va cau, le cau
nang o » nang co, nang ho, nang ro
o hoi » co hoi, o hoc, o hai

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 van nang o hoi. hieu ((ve cau) OR (ve cac)) truc van hanh de ((su triet) or (cua tu))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach van nang o hoi. hieu ((ve cau) OR (ve cac)) truc van hanh de ((su triet) OR (cua tu))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach van nang o hoi. hieu ((ve cau) OR (ve cac)) truc van hanh de ((su triet) or (cua tu))*".