Perhaps you should try some spelling variations:
vat thanh » dat thanh, gat thanh, tat thanh
thanh vi » hanh vi, thanh va, thanh ve
cam thuc » am thuc, nam thuc, cam thu
su sach » vu sach
tang ma » mang may, tang van
hieu ve » hieu va, hieu van
cua tre » cua te, cuu tre, cua triet
nang ma » sang ma, nang cao, mang may
so sach » so sanh, bo sach, co sach
ve cam » ve cham, ve cac, va cam
vi cua » vai cua, di cua

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