Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
tang ma » mang may, tang van
cham lo » cham o, cam lo, cham soc
va tinh » may tinh
tinh va » tich va, trinh van, trinh vat
cua tre » cua te, cuu tre, cua triet
y tang » ky tang, 6 tang, 7 tang
nam lo » nam bo, nam so, nam co
va cua » va chua, via cua, ca cua

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 y tang ma hoa. hieu qua ((cham lo) or (nam lo)) va tinh va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach y tang ma hoa. hieu qua ((cham lo) OR (nam lo)) va tinh va cua tre.
• Adding a wildcard symbol may retrieve word variants: thu sach y tang ma hoa. hieu qua ((cham lo) or (nam lo)) va tinh va cua tre*.