Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
sach thu » sach thue, sach thieu, sach tham
han tai » hang tai, nhan tai, van tai
dao duc » giao duc, tao duoc
cao duc » cao suc, giao duc, tao duoc
sach ty » sach y, sach tu, xach tay
nang xa » nang x, lang xa, nang ma
va han » va phan, van han, va hanh
cuc te » cua te, cuc thue, cuc tieu

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: te ((sach ty) OR (sach thu)) nang xa hoi. hieu van ((cao duc) or (dao duc)) va han tai cuc te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te ((sach ty) OR (sach thu)) nang xa hoi. hieu van ((cao duc) OR (dao duc)) va han tai cuc te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te ((sach ty) OR (sach thu)) nang xa hoi. hieu van ((cao duc) or (dao duc)) va han tai cuc te".
• Adding a wildcard symbol may retrieve word variants: te ((sach ty) OR (sach thu)) nang xa hoi. hieu van ((cao duc) or (dao duc)) va han tai cuc te*.