Perhaps you should try some spelling variations:
thanh van » thanh san, thanh toan, thanh phan
thu sach » thuat sach, thuoc sach, thu hoach
tu sach » su sach, te sach, tu cach
hieu va » lieu va, hieu qua
tang xa » trang xa, tang ma, lang xa
ky tang » ky nang, ky dang, kho tang
va cam » va cham, va cac, va cao
tuc va » thuc va, truc va, duc va
van va » van vat, van van, ban va
thiet* » thieu*

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) OR (thu sach)) ky tang xa hoi. hieu va cam ((tuc va) or (tuc xa)) thanh van va thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) ky tang xa hoi. hieu va cam ((tuc va) OR (tuc xa)) thanh van va thiet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (thu sach)) ky tang xa hoi. hieu va cam ((tuc va) or (tuc xa)) thanh van va thiet*".