Perhaps you should try some spelling variations:
cham duc » pham duc, cham soc, pham duy
cau tren » cu tren, dau tren, ca tren
nang ma » tang ma, sang ma, nang cao
hieu va » lieu va, hieu qua
va cham » va chat, va tham
va hanh » van hanh, va thanh, va danh
hanh ve » hanh vi, hanh va, hanh kem
ve cau » ke cau, va cau, ve cac

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu cac ky ((nang ma) or (nang x)) hoi. hieu va cham duc va hanh ve cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu cac ky ((nang ma) OR (nang x)) hoi. hieu va cham duc va hanh ve cau tren.
• Adding a wildcard symbol may retrieve word variants: tu cac ky ((nang ma) or (nang x)) hoi. hieu va cham duc va hanh ve cau tren*.