Perhaps you should try some spelling variations:
dan hanh » dang hanh, dan khanh, dan thanh
thuc dan » thuc hanh, hoc dan, thuc vat
te sach » toc sach
cuu tre » cua tre, cau tren, cau treo
so sach » so sanh, bo sach, co sach
tang xa » trang xa, tang ma, lang xa
ve cac » va cac, vien cac
y tang » ky tang, 6 tang, 7 tang
vi cuu » vi luu, vinh cuu
ve cam » ve cham, va cam, ve cai

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((te sach) or (so sach)) y tang xa hoi. hieu ((ve cam) or (ve cac)) thuc dan hanh vi cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (so sach)) y tang xa hoi. hieu ((ve cam) OR (ve cac)) thuc dan hanh vi cuu tre.
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (so sach)) y tang xa hoi. hieu ((ve cam) or (ve cac)) thuc dan hanh vi cuu tre*.