Perhaps you should try some spelling variations:
thieu nien » thien nhien
nien cac » vien cac, dien cac, bien cac
tu sach » thu sach, su sach, te sach
ky lang » ky nang, ky dang, tay lang
ky tang » ky nang, ky dang, kho tang
da nang » cam nang, kha nang, cao nang
doi cua » hoi cua
cac tu » cac thu, cach tu, cac du
tu da » tu dat, tu dau, tu dan

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 ((ky lang) or (ky tang)) xa hoi. thieu nien cac tu da nang ((doi cua) or (dai cua)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ky lang) OR (ky tang)) xa hoi. thieu nien cac tu da nang ((doi cua) OR (dai cua)) triet.
• Adding a wildcard symbol may retrieve word variants: tu sach ((ky lang) or (ky tang)) xa hoi. thieu nien cac tu da nang ((doi cua) or (dai cua)) triet*.