Perhaps you should try some spelling variations:
va hanh » van hanh, va thanh, va danh
hieu va » lieu va, hieu qua
cua tre » cua te, cuu tre, cua triet
nang ma » tang ma, sang ma, nang cao
sach ty » sach tu, sach thu, xach tay
cam lo » nam lo, cam ly
vi cua » vai cua, di cua
cam o » cham o, ca o, tam o

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

• Performing a fuzzy search may retrieve terms with similar spellings: te ((sach y) or (sach ty)) nang ma hoa. hieu va ((cam lo) or (cam o)) va hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te ((sach y) OR (sach ty)) nang ma hoa. hieu va ((cam lo) OR (cam o)) va hanh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: te ((sach y) or (sach ty)) nang ma hoa. hieu va ((cam lo) or (cam o)) va hanh vi cua tre*.