Perhaps you should try some spelling variations:
thu sach » thuat sach, thuoc sach, thu hoach
phan duc » pham duc, phan tu, phan dau
va hanh » van hanh, va thanh, va danh
hieu ke » hieu kem, chieu ke, hieu ky
tu sach » su sach, te sach, tu cach
nang xa » nang x, lang xa, nang ma
tu nang » tru nang, tu nong, tu nano
ke phan » ve phan, kenh phan, ke thang
oi su » ki su, vi su
ve su » va su

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)) tu nang xa hoi. hieu ke phan duc va hanh ((oi su) or (ve su)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) tu nang xa hoi. hieu ke phan duc va hanh ((oi su) OR (ve su)) triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (thu sach)) tu nang xa hoi. hieu ke phan duc va hanh ((oi su) or (ve su)) triet".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (thu sach)) tu nang xa hoi. hieu ke phan duc va hanh ((oi su) or (ve su)) triet*.