Perhaps you should try some spelling variations:
thien van » thi van
thu sach » thuat sach, thuoc sach, thu hoach
dat quoc » dat nuoc, dat duoc, dan quoc
than cua » nhan cua, thai cua, ban cua
van dang » van dong, van dung, van nang
va dang » va nang, va lang, da dang
van dat » van dao, van dau, dan dat
lang xa » lang ha, dang xay, lang van
ky lang » ky nang, ky dang, ky tang
tu sach » su sach, te sach, tu cach
cua tre » cua te, cuu tre, cua triet

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) or (tu sach)) ky lang xa hoi. thien van dat quoc ((va dang) OR (van dang)) than cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thu sach) OR (tu sach)) ky lang xa hoi. thien van dat quoc ((va dang) OR (van dang)) than cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((thu sach) or (tu sach)) ky lang xa hoi. thien van dat quoc ((va dang) OR (van dang)) than cua tre".
• Adding a wildcard symbol may retrieve word variants: ((thu sach) or (tu sach)) ky lang xa hoi. thien van dat quoc ((va dang) OR (van dang)) than cua tre*.