Perhaps you should try some spelling variations:
thien van » thi van
nhan thuc » nhan luc, dan thuc, toan thuc
dan khanh » dang khanh, van khanh, dat khanh
van nhan » van phan, van thanh, danh nhan
ban hanh » ban hang
cac tren » cau tren, rac tren, tac tren
co sach » bo sach, cuon sach, hoc sach
sach ky » sac ky, sach y, sach ty
ca tren » cau tren, cu tren, la tren

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

• Performing a fuzzy search may retrieve terms with similar spellings: co sach ky nang x ho. thien van nhan thuc ((ban hanh) or (dan khanh)) va ((cac tren) OR (ca tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: co sach ky nang x ho. thien van nhan thuc ((ban hanh) OR (dan khanh)) va ((cac tren) OR (ca tren)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "co sach ky nang x ho. thien van nhan thuc ((ban hanh) or (dan khanh)) va ((cac tren) OR (ca tren))".
• Adding a wildcard symbol may retrieve word variants: co sach ky nang x ho. thien van nhan thuc ((ban hanh) or (dan khanh)) va ((cac tren) OR (ca tren))*.