Perhaps you should try some spelling variations:
sach van » sach han, sach va, bach van
hieu van » hieu va, thien van, hieu ve
cam thuc » am thuc, cam thu, can thuc
nam thuc » nam thuoc, am thuc, nam thu
vat hanh » vat thanh, van hanh, va hanh
su sach » so sach, vu sach
hanh di » hanh vi, hanh de, hang di
cuu tre » cua tre, cau tren, cau treo
dong x » dong xa, dong y, dong o
di cuu » di cau, di cua, dinh cuu
x hoi » xa hoi, o hoi, x ho

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: su sach van dong x hoi. ((hieu van) or (lieu va)) ((cam thuc) or (nam thuc)) vat hanh di cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach van dong x hoi. ((hieu van) OR (lieu va)) ((cam thuc) OR (nam thuc)) vat hanh di cuu tre.
• Adding a wildcard symbol may retrieve word variants: su sach van dong x hoi. ((hieu van) or (lieu va)) ((cam thuc) or (nam thuc)) vat hanh di cuu tre*.