Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
hang tai » hang va, dung tai
nang mai » nang ma, nang tai, lang mai
mai hoi » mai khoi, dai hoi, lai hoi
hieu va » lieu va
sach ky » sac ky, sach y, sach ty
cham lo » cham o, cam lo, cham hoi
va hang » van hang, va nang, va lang
tai cua » thai cua, tai cuc, tri cua
cua tre » cua te, cuu tre, cua triet

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach ky nang mai hoi. ((hieu va) or (hieu qua)) ((cham lo) OR (cham soc)) va hang tai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky nang mai hoi. ((hieu va) OR (hieu qua)) ((cham lo) OR (cham soc)) va hang tai cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ky nang mai hoi. ((hieu va) or (hieu qua)) ((cham lo) OR (cham soc)) va hang tai cua tre*".