Perhaps you should try some spelling variations:
cam truc » cau truc, nam truc, lam truoc
truc van » truc va, thuc van, truc ban
van hanh » van thanh, ban hanh, van anh
su sach » so sach, vu sach
nang ma » tang ma, sang ma
hieu va » lieu va, hieu qua
cua tre » cua te, cuu tre, cua triet
va cam » va cham, va cac, va cao
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 y ((nang ma) or (((mang may) or (nang cao)))) hoi. hieu va cam truc van hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach y ((nang ma) OR (((mang may) OR (nang cao)))) hoi. hieu va cam truc van hanh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: su sach y ((nang ma) or (((mang may) or (nang cao)))) hoi. hieu va cam truc van hanh vi cua tre*.