Perhaps you should try some spelling variations:
thien van » thi van
hieu van » hieu va, lieu va
vat hanh » vat thanh, van hanh, va hanh
cam thuc » am thuc, nam thuc, cam thu
hanh di » hanh vi, hanh de, hang di
su sach » so sach, vu sach
hieu ve » hieu va
cuu tre » cua tre, cau tren, cau treo
sach v » sach va, sach y, sach 2
v nang » va nang, vu nang, van nang
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 v nang x hoi. ((hieu ve) or (((hieu van) OR (thien van)))) cam thuc vat hanh di cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach v nang x hoi. ((hieu ve) OR (((hieu van) OR (thien van)))) cam thuc vat hanh di cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach v nang x hoi. ((hieu ve) or (((hieu van) OR (thien van)))) cam thuc vat hanh di cuu tre".
• Adding a wildcard symbol may retrieve word variants: su sach v nang x hoi. ((hieu ve) or (((hieu van) OR (thien van)))) cam thuc vat hanh di cuu tre*.