Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
lang van » dang van, tang van, hoang van
nam thuc » nam thuoc, am thuc, nam thu
thuc dan » thuc hanh, hoc dan, thuc vat
cau tren » cu tren, dau tren, ca tren
lang xa » lang ha, dang xay
hieu va » lieu va, hieu qua
dan dan » dang dan, ban dan, dao dan
dan vai » dan va, dan tai, dan vat
vai cau » va cau, van cau, vai cac
va nam » van nam, ha nam, va nay

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 ((lang xa) or (lang van)) hoi. hieu va nam thuc dan dan vai cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc sach y ((lang xa) OR (lang van)) hoi. hieu va nam thuc dan dan vai cau tren.
• Adding a wildcard symbol may retrieve word variants: hoc sach y ((lang xa) or (lang van)) hoi. hieu va nam thuc dan dan vai cau tren*.