Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
va triet » va thiet, ve triet, cua triet
hanh tai » thanh tai, hang tai, han tai
van hanh » van thanh, ban hanh, van anh
cham duc » pham duc, cham soc, pham duy
va trien » va truyen, va thiet, va tuyen
hieu su » hieu sau, tieu su, hieu so
su cham » su pham, tu cham, vu cham
duc van » duc va, duc tan, duc manh
tang ma » mang may, tang van

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach nha ((tang ma) or (nang x)) hoi. hieu su cham duc van hanh tai ((va triet) OR (va trien))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach nha ((tang ma) OR (nang x)) hoi. hieu su cham duc van hanh tai ((va triet) OR (va trien))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach nha ((tang ma) or (nang x)) hoi. hieu su cham duc van hanh tai ((va triet) OR (va trien))*".