Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
dau tren » dau tien, dat tren, dau tieng
hieu va » lieu va, hieu qua
cam loc » cam lo
cuu tre » cua tre, cau tren, cau treo
y nang » ly nang, v nang, may nang
va cam » va cham, va cac, va cao
loc va » hoc va, luc va
va dan » ca dan, va dao, va dau
dan tu » danh tu, dan su, ban tu

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 dan tu ((cuu tre) or (dau 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 dan tu ((cuu tre) OR (dau tren)).
• Adding a wildcard symbol may retrieve word variants: hoc sach ((y nang) or (ky nang)) xa hoi. hieu va cam loc va dan tu ((cuu tre) or (dau tren))*.