Perhaps you should try some spelling variations:
nam thuoc » nam thuc, nam thu, nha thuoc
tinh tai » trinh tai, tinh thai, tinh hai
tu sach » thu sach, su sach, te sach
cam tuc » cam xuc, cam tu, nam thuc
va tinh » may tinh
cuc tre » duc tre, cua tre, cuu tre
hieu ve » hieu va, hieu van
ty bang » te bang, ty hang, tao bang

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ((ty bang) OR (ty xang)) cau hoi. hieu ve ((cam tuc) or (nam thuoc)) va tinh tai cuc tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ty bang) OR (ty xang)) cau hoi. hieu ve ((cam tuc) OR (nam thuoc)) va tinh tai cuc tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((ty bang) OR (ty xang)) cau hoi. hieu ve ((cam tuc) or (nam thuoc)) va tinh tai cuc tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ((ty bang) OR (ty xang)) cau hoi. hieu ve ((cam tuc) or (nam thuoc)) va tinh tai cuc tre*.