Perhaps you should try some spelling variations:
van quang » van quan, tran quang, van tuan
van nang » van ban, van dong, van dung
dan hanh » dang hanh, dan khanh, dan thanh
thuc dan » thuc hanh, hoc dan, thuc vat
tu sach » thu sach, su sach, te sach
vi cua » vai cua, di cua
ve tai » te tai, de tai, le tai
va cam » va cham, va cac, va cao
cua te » cua tu

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((van nang) OR (van quang)) xa hoi. hieu ((ve tai) OR (va cam)) thuc dan hanh vi cua te~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((van nang) OR (van quang)) xa hoi. hieu ((ve tai) or (va cam)) thuc dan hanh vi cua te~".
• Adding a wildcard symbol may retrieve word variants: tu sach ((van nang) OR (van quang)) xa hoi. hieu ((ve tai) or (va cam)) thuc dan hanh vi cua te*.