Perhaps you should try some spelling variations:
cam thuc » am thuc, nam thuc, cam thu
vat hanh » vat thanh, van hanh, va hanh
ban hanh » ban hang
su sach » so sach, vu sach
sach ly » sach y, sach lo, sach ty
ly nang » ky nang, ly hang, ly vang
hieu ve » hieu va, hieu van
cua tre » cua te, cuu tre, cua triet
ve cam » ve cham, ve cac, va cam
di cua » dai cua, doi cua, de 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 ly nang x ho. hieu ve cam thuc ((vat hanh) or (ban hanh)) di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ly nang x ho. hieu ve cam thuc ((vat hanh) OR (ban hanh)) di cua tre.
• Adding a wildcard symbol may retrieve word variants: su sach ly nang x ho. hieu ve cam thuc ((vat hanh) or (ban hanh)) di cua tre*.