Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
vat hanh » vat thanh, van hanh, va hanh
cuu thuc » cuu tac
van cuu » van cau, van chu, van cu
sach ky » sac ky, sach y, sach ty
tu sach » thu sach, su sach, te sach
nang ma » tang ma, sang ma, nang cao
nang xa » nang x, lang xa, mang xa
te cua » tue cua, le cua
de cua » le cua, dieu cua

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