Perhaps you should try some spelling variations:
thieu nien » thien nhien
hanh thai » nhanh thai, hinh thai, hanh tai
hieu vien » hieu hien, hieu viec, hieu tieng
thai cua » than cua, tai cuc, tri cua
su sach » so sach, vu sach
va hanh » van hanh, va thanh, va danh
cac dai » cac dan, cac bai, can dai
ky tang » ky nang, ky dang, kho tang
ky sang » ky nang, ky dang, duy sang
dai va » mai va
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 ((ky sang) or (ky tang)) ma hoa. ((hieu vien) or (thieu nien)) cac dai va hanh thai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((ky sang) OR (ky tang)) ma hoa. ((hieu vien) OR (thieu nien)) cac dai va hanh thai cua te.
• Adding a wildcard symbol may retrieve word variants: su sach ((ky sang) or (ky tang)) ma hoa. ((hieu vien) or (thieu nien)) cac dai va hanh thai cua te*.