Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
cau tren » cu tren, dau tren, ca tren
hieu va » lieu va, hieu qua
cam loc » cam lo
va danh » va dinh, va dan, va hanh
danh du » danh dau, danh tu, dinh du
y nang » ly nang, v nang, may nang
va cam » va cham, va cac, va cao
loc va » hoc va, luc va
du cau » cu cau, da 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: hoc sach ((y nang) or (ky nang)) xa hoi. hieu va cam loc va danh du cau tren~.
• 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 du cau tren.
• Adding a wildcard symbol may retrieve word variants: hoc sach ((y nang) or (ky nang)) xa hoi. hieu va cam loc va danh du cau tren*.