Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
toc sach » hoc sach, doc sach, thuoc sach
han tai » hang tai, nhan tai, van tai
dao duc » giao duc, tao duoc
cao duc » cao suc, giao duc, tao duoc
nang xa » nang x, lang xa, nang ma
ty nang » ky nang, ty xang, ty hang
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) OR (toc sach)) ty 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) OR (toc sach)) ty 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) OR (toc sach)) ty 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) OR (toc sach)) ty nang xa hoi. hieu van ((cao duc) or (dao duc)) va han tai cuc te*.