Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
cau tren » cu tren, dau tren, cau treo
van hanh » van thanh, ban hanh, van anh
hieu van » hieu va, thien van, lieu va
hieu ve » hieu va
sach ky » sac ky, sach y, sach ty
tang xa » trang xa, tang ma, lang xa
ky tang » ky nang, ky dang, kho tang
ca tren » cu tren, la tren, co tren
xu van » tu van, vu van, su van

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 ky tang xa hoi. ((hieu ve) OR (hieu van)) chao xu van hanh vi ((cau tren) or (ca tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky tang xa hoi. ((hieu ve) OR (hieu van)) chao xu van hanh vi ((cau tren) OR (ca tren)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ky tang xa hoi. ((hieu ve) OR (hieu van)) chao xu van hanh vi ((cau tren) or (ca tren))".
• Adding a wildcard symbol may retrieve word variants: thu sach ky tang xa hoi. ((hieu ve) OR (hieu van)) chao xu van hanh vi ((cau tren) or (ca tren))*.