Perhaps you should try some spelling variations:
thai hoc » dai hoc, bai hoc, thai do
cau tren » cu tren, dau tren, ca tren
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
hieu va » lieu va, hieu qua
hoi hoc » hoa hoc, khoa hoc, hoi chuc
va hanh » van hanh, va thanh, va danh
vi cau » va cau, ve cau, di cau
x hoi » xa hoi, o hoi, 5 hoi

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