Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
thuc cao » thuoc cao, thuc co, thuc can
nam thuc » nam thuoc, am thuc, nam thu
vai cuu » vai cua
dan vai » dan va, dan tai, dan vat
cao dan » cao dang, cao danh, cac dan
hieu va » lieu va
sach ky » sac ky, sach y, sach ty
dung ha » dung va, dung he, dung khoa
dang xa » dang xay, lang xa, dang ha
cuu tre » cua tre, cau tren, cau treo

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 ky ((dang xa) or (dung ha)) hoi. ((hieu va) or (hieu qua)) nam thuc cao dan vai cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc sach ky ((dang xa) OR (dung ha)) hoi. ((hieu va) OR (hieu qua)) nam thuc cao dan vai cuu tre.
• Adding a wildcard symbol may retrieve word variants: hoc sach ky ((dang xa) or (dung ha)) hoi. ((hieu va) or (hieu qua)) nam thuc cao dan vai cuu tre*.