Perhaps you should try some spelling variations:
dan thanh » dang thanh, danh thanh, ban thanh
thanh te » thanh ve, thanh de, thanh le
thuc dan » thuc hanh, hoc dan, thuc vat
van cuu » van cau, van chu, van cua
sach ty » sach y, sach tu, sach thu
tu sach » thu sach, su sach, te sach
nang xa » nang x, lang xa, mang xa
nang ma » tang ma, sang ma, nang cao
van cu » van cau, van chu, van cua
te cua » tue cua, le cua, de cua
cua te » cua tu

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 ((nang xa) or (nang ma)) hoi. hieu ((van cuu) or (van cu)) thuc dan thanh te cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty ((nang xa) OR (nang ma)) hoi. hieu ((van cuu) OR (van cu)) thuc dan thanh te cua te.
• Adding a wildcard symbol may retrieve word variants: tu sach ty ((nang xa) or (nang ma)) hoi. hieu ((van cuu) or (van cu)) thuc dan thanh te cua te*.