Perhaps you should try some spelling variations:
thanh ha » thanh hoa, thanh hai, nhanh ha
su sach » so sach, vu sach
cam thu » nam thu, cac thu, ca thu
sach ky » sac ky, sach y, sach ty
cua tre » cua te, cuu tre, cua triet
hieu ve » hieu va, hieu van
tang ma » mang may, tang van
nang xa » nang x, lang xa, nang ma
thu va » thuc va, thue va, tu va
ve cam » ve cham, ve cac, va cam

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ky ((nang xa) or (tang ma)) hoi. hieu ve cam thu va ((hanh vi) or (thanh ha)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky ((nang xa) OR (tang ma)) hoi. hieu ve cam thu va ((hanh vi) OR (thanh ha)) cua tre.
• Adding a wildcard symbol may retrieve word variants: su sach ky ((nang xa) or (tang ma)) hoi. hieu ve cam thu va ((hanh vi) or (thanh ha)) cua tre*.