Perhaps you should try some spelling variations:
tinh gian » tinh gia, tinh giao, trinh giang
sach thu » sach thue, sach thieu, sach tham
hieu van » hieu va, thien van, lieu va
van phan » van phong, van thanh, luan phan
phan duc » pham duc, phan tu, phan dau
sach tu » cach tu, sach ty, sach uu
duc may » duc mau, duc man, duc manh
xu te » tu te

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 tu) or (sach thu)) nang x ho. hieu van phan duc may tinh gian xu te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te ((sach tu) OR (sach thu)) nang x ho. hieu van phan duc may tinh gian xu te.
• Adding a wildcard symbol may retrieve word variants: te ((sach tu) or (sach thu)) nang x ho. hieu van phan duc may tinh gian xu te*.