Perhaps you should try some spelling variations:
thien van » thi van
thu sach » thuat sach, thuoc sach, thu hoach
duc tren » duoc tren, dua tren, duc tien
tu sach » su sach, te sach, tu cach
ky lang » ky nang, ky tang, tay lang
ky dang » ky nang, ky danh
nam duc » nam duoc, pham duc, nam thuc
va hang » van hang, va nang, va lang
hang do » hang doi, dang do, hang di
do duc » dao duc, do duy

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 lang) or (ky dang)) xa hoi. thien van nam duc va hang do duc tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) ((ky lang) OR (ky dang)) xa hoi. thien van nam duc va hang do duc tren*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (thu sach)) ((ky lang) or (ky dang)) xa hoi. thien van nam duc va hang do duc tren*".