Perhaps you should try some spelling variations:
vat hanh » vat thanh, van hanh, va hanh
va triet » va trien, ve triet, cua triet
su sach » so sach, vu sach
sach ly » sach y, sach lo, sach ty
ly nang » ky nang, ly hang, ly vang
nang xa » nang x, lang xa, nang ma
hanh va » hang va, hanh vi
ve nam » he nam, le nam, te nam
va nam » van nam, ha nam, va nay
thiet » thieu

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ly nang xa hoi. hieu ((ve nam) OR (va nam)) thuc vat hanh va ((va triet) or (va thiet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ly nang xa hoi. hieu ((ve nam) OR (va nam)) thuc vat hanh va ((va triet) OR (va thiet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ly nang xa hoi. hieu ((ve nam) OR (va nam)) thuc vat hanh va ((va triet) or (va thiet))".
• Adding a wildcard symbol may retrieve word variants: su sach ly nang xa hoi. hieu ((ve nam) OR (va nam)) thuc vat hanh va ((va triet) or (va thiet))*.