Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
hieu va » lieu va, hieu qua
cam loc » cam lo
va danh » va dinh, va dan, dia danh
va hanh » van hanh, va thanh, ban hanh
cuu tre » cua tre, cau tren, cau treo
y nang » ly nang, v nang, may nang
va cam » va cham, va cac, va cao
du cuu » tu cuu

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: hoc sach ((y nang) or (ky nang)) xa hoi. hieu va cam loc ((va danh) OR (va hanh)) du cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc sach ((y nang) OR (ky nang)) xa hoi. hieu va cam loc ((va danh) OR (va hanh)) du cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc sach ((y nang) or (ky nang)) xa hoi. hieu va cam loc ((va danh) OR (va hanh)) du cuu tre".
• Adding a wildcard symbol may retrieve word variants: hoc sach ((y nang) or (ky nang)) xa hoi. hieu va cam loc ((va danh) OR (va hanh)) du cuu tre*.