Perhaps you should try some spelling variations:
thanh dan » thanh san, thanh van, thanh dat
dan thanh » dang thanh, danh thanh, ban thanh
va trien » va truyen, va thiet, va tuyen
thuc dan » thuc hanh, hoc dan, thuc vat
sach ty » sach y, sach tu, sach thu
va cham » va chat, va tham
tu sach » thu sach, su sach, te sach
lang xa » lang ha, dang xay, lang van
ve chim » va chim, ve cham, ve chinh
ang xa » mang xa, dang xay, hoang xa
dan va » doan va, dan ca, ban va

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ty ((ang xa) or (lang xa)) hoi. hieu ((ve chim) or (va cham)) thuc dan thanh dan va trien~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty ((ang xa) OR (lang xa)) hoi. hieu ((ve chim) OR (va cham)) thuc dan thanh dan va trien.
• Adding a wildcard symbol may retrieve word variants: tu sach ty ((ang xa) or (lang xa)) hoi. hieu ((ve chim) or (va cham)) thuc dan thanh dan va trien*.