Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
tri nang » thi nang, tra nang, tri bang
hieu van » hieu va, thien van, lieu va
cau tren » cu tren, dau tren, ca tren
van cam » van nam, van lam, van cau
xuc ban » duc ban, quoc ban, xuat ban
cuc ban » cua ban, cac ban, cuu ban
tu nong » tu dong, tu cong, tu tong
vi cau » va cau, ve cau, di cau

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 ((tu nong) or (tri nang)) xa hoi. hieu van cam ((xuc ban) OR (cuc ban)) hanh vi cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ((tu nong) OR (tri nang)) xa hoi. hieu van cam ((xuc ban) OR (cuc ban)) hanh vi cau tren*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ((tu nong) or (tri nang)) xa hoi. hieu van cam ((xuc ban) OR (cuc ban)) hanh vi cau tren*".