Perhaps you should try some spelling variations:
va thanh » gia thanh, ban thanh, va tinh
cham duc » pham duc, cham soc, pham duy
su sach » so sach, vu sach
lam cuu » lam chu, lam cua, cham cuu
va hanh » van hanh, va danh, ban hanh
hieu va » lieu va, hieu qua
sach tu » sach thu, cach tu, sach ty
hieu vu » hieu ve, hieu su, dieu vu
tong ma » tang ma, dong ma, cong ma
tu tong » tu tuong, tu trong, tu dong
cuu tre » cua tre, cau tren, cau treo
ma hoi » mai hoi, xa hoi, ma hoa

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 tu tong ma hoi. ((hieu vu) or (hieu va)) cham duc ((va hanh) OR (va thanh)) lam cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach tu tong ma hoi. ((hieu vu) OR (hieu va)) cham duc ((va hanh) OR (va thanh)) lam cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach tu tong ma hoi. ((hieu vu) or (hieu va)) cham duc ((va hanh) OR (va thanh)) lam cuu tre".
• Adding a wildcard symbol may retrieve word variants: su sach tu tong ma hoi. ((hieu vu) or (hieu va)) cham duc ((va hanh) OR (va thanh)) lam cuu tre*.