Perhaps you should try some spelling variations:
sach thu » sach thue, sach thieu, sach tham
hieu van » hieu va, thien van, lieu va
van pham » san pham, van phan, van phat
tan hanh » tan thanh, tang hanh, toan hanh
hanh dao » lanh dao, thanh dat, thanh dam
va triet » va trien, ve triet, cua triet
sach ty » sach y, sach tu, xach tay
nang xa » nang x, lang xa, nang ma
thiet » thieu

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) or (sach thu)) nang xa hoi. hieu van pham duc tan hanh dao ((va triet) or (va thiet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ty) OR (sach thu)) nang xa hoi. hieu van pham duc tan hanh dao ((va triet) OR (va thiet)).
• Adding a wildcard symbol may retrieve word variants: tu ((sach ty) or (sach thu)) nang xa hoi. hieu van pham duc tan hanh dao ((va triet) or (va thiet))*.