Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
cam thuc » am thuc, nam thuc, cam thu
tri cuu » tri cua, tra cuu, trinh cuu
va dinh » van dinh, va kinh, va tinh
va danh » va dan, va hanh, dia danh
cuu tre » cua tre, cau tren, cau treo
hieu ve » hieu va, hieu van
mang xa » lang xa, mang may, dang xay
tu mang » tu manh, tu lang, tu quang
bo sach » co sach
ve cam » ve cham, ve cac, va cam

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((hoc sach) or (bo sach)) tu mang xa hoi. hieu ve cam thuc ((va danh) or (va dinh)) tri cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((hoc sach) OR (bo sach)) tu mang xa hoi. hieu ve cam thuc ((va danh) OR (va dinh)) tri cuu tre.
• Adding a wildcard symbol may retrieve word variants: ((hoc sach) or (bo sach)) tu mang xa hoi. hieu ve cam thuc ((va danh) or (va dinh)) tri cuu tre*.