Perhaps you should try some spelling variations:
tang mai » tang ma, tang tai, lang mai
hanh lam » thanh lap, hanh kem, hanh va
su sach » so sach, vu sach
hieu va » lieu va, hieu qua
lam cua » nam cua, lam chat
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, cua triet
hieu ve » hieu van
sach ty » sach y, sach tu, sach thu
hieu vu » hieu su, dieu vu, hieu qua
mai hoi » mai khoi, dai hoi, lai hoi
ty tang » tay tang, ty xang, ty hang

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