Perhaps you should try some spelling variations:
toc sach » doc sach, thuoc sach, nuoc sach
hieu van » hieu va, thien van, lieu va
van hanh » van thanh, ban hanh, van anh
van tham » van thanh, van tuan, van chat
tham soc » cham soc, tham nuoc, thai son
hoc sach » hoc sinh, hoc cac, hoc anh
lang xa » lang ha, dang xay, lang van
va dinh » van dinh, va kinh, va tinh
cuu tre » cua tre, cau tren, cau treo
vi cuu » vi luu, vinh cuu

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((toc sach) OR (hoc sach)) _ lang xa hoi. hieu van tham soc ((van hanh) or (va dinh)) vi cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (hoc sach)) _ lang xa hoi. hieu van tham soc ((van hanh) OR (va dinh)) vi cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((toc sach) OR (hoc sach)) _ lang xa hoi. hieu van tham soc ((van hanh) or (va dinh)) vi cuu tre".
• Adding a wildcard symbol may retrieve word variants: ((toc sach) OR (hoc sach)) _ lang xa hoi. hieu van tham soc ((van hanh) or (va dinh)) vi cuu tre*.