Perhaps you should try some spelling variations:
sach tham » sach nha
va triet » va thiet, va trien, ve triet
hanh dao » lanh dao, thanh dat, thanh dam
tan hanh » tan thanh, tang hanh, toan hanh
van cham » van chat, van tham, va cham
hieu van » hieu va, thien van, lieu va
soc tan » hoc tan, so tan, soc dan
sach ty » sach y, sach tu, sach thu
nang xa » lang xa, nang ma, mang xa
dao va » dao van, tao va, do va

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 ty) or (sach tham)) ((nang xa) OR (nang x)) hoi. hieu van cham soc tan hanh dao va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ty) OR (sach tham)) ((nang xa) OR (nang x)) hoi. hieu van cham soc tan hanh dao va triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ty) or (sach tham)) ((nang xa) OR (nang x)) hoi. hieu van cham soc tan hanh dao va triet".
• Adding a wildcard symbol may retrieve word variants: tu ((sach ty) or (sach tham)) ((nang xa) OR (nang x)) hoi. hieu van cham soc tan hanh dao va triet*.