Perhaps you should try some spelling variations:
sach thue » sach thu, sach thieu, sach tham
hieu van » hieu va, thien van, lieu va
cam thuc » am thuc, nam thuc, cam thu
vat danh » va danh, van danh, luat danh
danh vai » danh sai, danh va, doanh van
tu sach » thu sach, su sach, te sach
mang xa » mang may, dang xay, mang cua
lang xa » lang ha, dang xay, lang van
van cam » van nam, van lam, van cau
vai cua » dai cua, hai cua, lai cua
cua tre » cua te, cuu tre, cua triet

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 thue ((mang xa) or (lang xa)) hoi. hieu van cam thuc vat danh vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach thue ((mang xa) OR (lang xa)) hoi. hieu van cam thuc vat danh vai cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sach thue ((mang xa) or (lang xa)) hoi. hieu van cam thuc vat danh vai cua tre*.