Perhaps you should try some spelling variations:
cham thuc » nham thuc, pham thuc, tham thuc
vat hanh » vat thanh, van hanh, va hanh
cau tren » cu tren, dau tren, ca tren
su sach » so sach, vu sach
hieu ve » hieu va, hieu van
ve cham » va cham, ve chat, vu cham
hanh di » hanh vi, hanh de, hang di
sach v » sach va, sach y, sach 2
v nang » va nang, vu nang, van nang
di cau » da cau, diem cau
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 cham thuc vat hanh di cau tren~.
• Adding a wildcard symbol may retrieve word variants: su sach v nang x hoi. hieu ve cham thuc vat hanh di cau tren*.