Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, tam thuc
hieu van » hieu va, thien van, hieu ve
thu sach » thuat sach, thuoc sach, thu hoach
hanh di » hanh vi, hanh de, hang di
xa hanh » xa thanh, xa khanh, va hanh
thuc xa » thuc xay, tuc xa, thuc va
tu sach » su sach, te sach, tu cach
vang xa » lang xa, mang xa, ang xa
ly vang » ly hang, ly van, ly quang
cua tre » cua te, cuu tre, cua triet
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)) ly vang xa hoi. ((hieu van) or (lieu va)) tham thuc xa hanh di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) ly vang xa hoi. ((hieu van) OR (lieu va)) tham thuc xa hanh di cua tre.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thu sach)) ly vang xa hoi. ((hieu van) or (lieu va)) tham thuc xa hanh di cua tre*.