Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
thu sach » tu sach, thuat sach, thuoc sach
vien cac » vien bach, vien dai, vien da
hai cua » thai cua, dai cua, hoi cua
va hanh » van hanh, va thanh, va danh
va lanh » va lang, va danh, va anh
cac lao » ca lao, cac loai, cac giao
nang xa » nang x, lang xa, nang ma
su sach » so sach, vu sach
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: ((thu sach) or (su sach)) ky nang xa hoi. hieu vien cac lao ((va lanh) OR (va hanh)) hai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thu sach) OR (su sach)) ky nang xa hoi. hieu vien cac lao ((va lanh) OR (va hanh)) hai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((thu sach) or (su sach)) ky nang xa hoi. hieu vien cac lao ((va lanh) OR (va hanh)) hai cua tre".
• Adding a wildcard symbol may retrieve word variants: ((thu sach) or (su sach)) ky nang xa hoi. hieu vien cac lao ((va lanh) OR (va hanh)) hai cua tre*.