Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
thu sach » thuat sach, thuoc sach, thu hoach
xuat tuc » xuat thuc, luat tuc, xuat tu
van xuat » san xuat, va xuat, phan xuat
tang mai » tang ma, tang tai, lang mai
va hanh » van hanh, va thanh, va danh
tu sach » su sach, te sach, tu cach
mai hoi » mai khoi, dai hoi, lai hoi
ky tang » ky nang, ky dang, kho tang
va dan » ca dan, va dao, va dau
di cua » dai cua, doi cua, de 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) or (thu sach)) ky tang mai hoi. hieu van xuat tuc ((va hanh) or (va dan)) di cua vat~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) ky tang mai hoi. hieu van xuat tuc ((va hanh) OR (va dan)) di cua vat.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thu sach)) ky tang mai hoi. hieu van xuat tuc ((va hanh) or (va dan)) di cua vat*.