Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
thuc dan » hoc dan, thuc vat
tu sach » thu sach, su sach, te sach
hanh tu » anh tu, danh tu
sach ky » sac ky, sach y, sach ty
van cuu » van cau, van chu, van cu
nang xa » nang x, lang xa, mang xa
nang ma » tang ma, sang ma, nang cao
tu cua » hu cua, vu cua
cua tu » cua tuc, cua su, cua cu

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 dan) or (thuc hanh)) hanh tu cua tu~.
• 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 dan) OR (thuc hanh)) hanh tu cua tu.
• Adding a wildcard symbol may retrieve word variants: tu sach ky ((nang xa) or (nang ma)) hoi. hieu van cuu ((thuc dan) or (thuc hanh)) hanh tu cua tu*.