Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
vien cau » vien cac, vien cao, vien sau
thu sach » thuat sach, thuoc sach, thu hoach
van hanh » van thanh, ban hanh, van anh
va hanh » va thanh, va danh, ban hanh
hai cua » thai cua, dai cua, hoi cua
tu sach » su sach, te sach, tu cach
cau luc » cau truc, cau phuc
nang xa » nang x, lang xa, nang ma
cua tre » cua te, cuu tre, cua triet

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) or (thu sach)) ky nang xa hoi. hieu vien cau luc ((va hanh) OR (van hanh)) hai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) ky nang xa hoi. hieu vien cau luc ((va hanh) OR (van hanh)) hai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (thu sach)) ky nang xa hoi. hieu vien cau luc ((va hanh) OR (van hanh)) hai cua tre".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thu sach)) ky nang xa hoi. hieu vien cau luc ((va hanh) OR (van hanh)) hai cua tre*.