Perhaps you should try some spelling variations:
cam thuc » am thuc, nam thuc, cam thu
manh hai » lanh hai, minh hai, thanh hai
vu khach » vu khanh, vu khac, vay khach
danh hai » dang hai, lanh hai, danh hau
thuc day » thuc dan, thuc vat
su sach » so sach, vu sach
ca tren » cau tren, cu tren, la tren
hieu va » lieu va, hieu qua
nang ma » tang ma, sang ma, nang cao
ly nang » ky nang, ly hang, ly vang
ma hoi » mai hoi, xa hoi, ma hoa
va cam » va cham, va cac, va cao

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) or (vu khach)) ly nang ma hoi. hieu va cam thuc day ((danh hai) or (manh hai)) ca tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (vu khach)) ly nang ma hoi. hieu va cam thuc day ((danh hai) OR (manh hai)) ca tren.
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (vu khach)) ly nang ma hoi. hieu va cam thuc day ((danh hai) or (manh hai)) ca tren*.