Perhaps you should try some spelling variations:
dau truc » cau truc, doan truc, dau tu
dai truc » dai thuc, doan truc, dai trung
van hanh » van thanh, ban hanh, van anh
su sach » so sach, vu sach
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
nang xa » nang x, lang xa, nang ma
di cua » doi cua, de cua, do cua

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 ty nang xa hoi. lieu va ((dau truc) or (dai truc)) van hanh ((di cua) OR (dai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ty nang xa hoi. lieu va ((dau truc) OR (dai truc)) van hanh ((di cua) OR (dai cua)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ty nang xa hoi. lieu va ((dau truc) or (dai truc)) van hanh ((di cua) OR (dai cua)) tre".
• Adding a wildcard symbol may retrieve word variants: su sach ty nang xa hoi. lieu va ((dau truc) or (dai truc)) van hanh ((di cua) OR (dai cua)) tre*.