Perhaps you should try some spelling variations:
hoang van » hang va
hoc sach » hoc sinh, hoc cac, hoc anh
dang xay » dang van, van xay
thuc day » thuc dan, thuc vat
dan vai » dan va, dan tai, dan vat
thuc va » thuc vat, thuc dan
cu tren » tu tren, dua tren
hieu va » lieu va, hieu qua
vai cu » vai cua, van cu
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 ((dang xay) or (hoang van)) hoi. hieu va nam ((thuc va) or (thuc day)) dan vai cu tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc sach y ((dang xay) OR (hoang van)) hoi. hieu va nam ((thuc va) OR (thuc day)) dan vai cu tren.
• Adding a wildcard symbol may retrieve word variants: hoc sach y ((dang xay) or (hoang van)) hoi. hieu va nam ((thuc va) or (thuc day)) dan vai cu tren*.