Perhaps you should try some spelling variations:
cam thuc » am thuc, nam thuc, cam thu
hanh dua » hanh sua, hanh cua, hanh qua
dau tren » dau tien, dat tren, dau tieng
su sach » so sach, vu sach
hieu ve » hieu va, hieu van
hanh da » hanh dao, hanh va, hanh de
y nang » ky nang, ly nang, v nang
ve cam » ve cham, ve cac, va cam
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 y nang x hoi. hieu ve cam thuc vat ((hanh da) or (hanh dua)) dau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach y nang x hoi. hieu ve cam thuc vat ((hanh da) OR (hanh dua)) dau tren.
• Adding a wildcard symbol may retrieve word variants: su sach y nang x hoi. hieu ve cam thuc vat ((hanh da) or (hanh dua)) dau tren*.