Perhaps you should try some spelling variations:
thien van » thi van
toc sach » hoc sach, doc sach, thuoc sach
hanh han » hanh nhan, hanh phan, hanh san
duc hanh » duc thanh, duc anh, du hanh
van cao » van dao, van bao, van hao
ty nang » ty xang, ty hang, ly nang
cao duc » dao duc, cao suc, giao duc
vai va » mai va, dai va, hai va
vi va » vi van, vu va, bi va

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach ((ty nang) or (ky nang)) xa hoi. thien van cao duc hanh han ((vi va) or (vai va)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ((ty nang) OR (ky nang)) xa hoi. thien van cao duc hanh han ((vi va) OR (vai va)) triet.
• Adding a wildcard symbol may retrieve word variants: toc sach ((ty nang) or (ky nang)) xa hoi. thien van cao duc hanh han ((vi va) or (vai va)) triet*.