Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
duc tren » duoc tren, dua tren, duc tien
tu sach » thu sach, te sach, tu cach
su sach » so sach, vu sach
van cam » van nam, van lam, van cau
va hanh » van hanh, va thanh, va danh
y nang » ly nang, v nang, may nang
xuc va » duc va, tuc va, luc va
vi duc » vu duc, oi duc, ve duc

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