Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
van hanh » van thanh, ban hanh, van anh
cau tren » cu tren, dau tren, ca tren
xang cao » nang cao, lang cao, quang cao
cao hoi » cau hoi, co hoi, cao hoc
sach ty » sach y, sach tu, sach thu
va danh » va dinh, va hanh, dia danh
qua co » qua con, cua co, qua ca
co luc » coc luc, co luy
va dan » ca dan, va dao, va dau
ve cau » ke cau, va cau, ve cac

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuoc sach ty xang cao hoi. hieu qua co luc ((((va danh) or (van hanh))) or (va dan)) ve cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuoc sach ty xang cao hoi. hieu qua co luc ((((va danh) OR (van hanh))) OR (va dan)) ve cau tren.
• Adding a wildcard symbol may retrieve word variants: thuoc sach ty xang cao hoi. hieu qua co luc ((((va danh) or (van hanh))) or (va dan)) ve cau tren*.