Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
te sach » toc sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, mang xa
nang ma » tang ma, nang cao, mang may
sang ma » tang ma, sang tao, mang may
van hac » van hoc, van ha, van hai
hac duc » hoc duc, ha duc, thach duc
va hanh » van hanh, va thanh, va danh
hanh va » hang va, hanh vi
phat » phan, pham, phap

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

• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky ((nang xa) OR (((nang ma) OR (sang ma)))) hoi. hieu van hac duc va hanh va phat trien~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky ((nang xa) or (((nang ma) OR (sang ma)))) hoi. hieu van hac duc va hanh va phat trien~".
• Adding a wildcard symbol may retrieve word variants: te sach ky ((nang xa) or (((nang ma) OR (sang ma)))) hoi. hieu van hac duc va hanh va phat trien*.