Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
hieu van » hieu va, thien van, lieu va
va triet » va thiet, va trien, ve triet
van cam » van nam, van lam, van cau
cam duc » cam xuc, cao duc, pham duc
dan hai » doan hai, dang hai, dan khai
y nang » ly nang, may nang, day nang
v nang » va nang, vu nang, van nang
va dan » ca dan, va dao, va dau
hai va » hai van, thai va, hoi va

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 ((((y nang) OR (ky nang))) or (v nang)) xa hoi. hieu van cam duc va dan hai va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ((((y nang) OR (ky nang))) OR (v nang)) xa hoi. hieu van cam duc va dan hai va triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ((((y nang) OR (ky nang))) or (v nang)) xa hoi. hieu van cam duc va dan hai va triet".
• Adding a wildcard symbol may retrieve word variants: thu sach ((((y nang) OR (ky nang))) or (v nang)) xa hoi. hieu van cam duc va dan hai va triet*.