Perhaps you should try some spelling variations:
vat hanh » vat thanh, van hanh, va hanh
cam thuc » am thuc, nam thuc, cam thu
sach ky » sac ky, sach ty, sach kem
hieu va » lieu va, hieu qua
nang ma » tang ma, sang ma, nang cao
nang xa » nang x, lang xa, mang xa
lua tre » cua tre, luy tre, dua tren
va cam » va cham, va cac, va cao
vi lua » vi luu

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 ky) or (sach y)) ((nang xa) or (nang ma)) hoi. hieu va cam thuc vat hanh vi lua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach ky) OR (sach y)) ((nang xa) OR (nang ma)) hoi. hieu va cam thuc vat hanh vi lua tre.
• Adding a wildcard symbol may retrieve word variants: su ((sach ky) or (sach y)) ((nang xa) or (nang ma)) hoi. hieu va cam thuc vat hanh vi lua tre*.