Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
van pham » san pham, van phan, van phat
van hanh » van thanh, ban hanh, van anh
so sach » so sanh, bo sach, co sach
ty nang » ty xang, ty hang, ly nang
duc van » duc va, duc tan, duc manh
tai cua » thai cua, tri cua, dai cua
x hoi » xa hoi, o hoi, x ho

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach ((ty nang) OR (ky nang)) x hoi. hieu van pham duc van hanh ((tai cua) or (tai cuc)) te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ((ty nang) OR (ky nang)) x hoi. hieu van pham duc van hanh ((tai cua) OR (tai cuc)) te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ((ty nang) OR (ky nang)) x hoi. hieu van pham duc van hanh ((tai cua) or (tai cuc)) te".
• Adding a wildcard symbol may retrieve word variants: so sach ((ty nang) OR (ky nang)) x hoi. hieu van pham duc van hanh ((tai cua) or (tai cuc)) te*.