Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
hang hai » hoang hai, hang tai, thanh hai
hanh hai » thanh hai, nhanh hai, hanh tai
va triet » va thiet, va trien, ve triet
hieu ve » hieu va, hieu van
tuc van » thuc van, truc van, tuc va
ky danh » ky anh
ky dang » ky nang
cac tuc » cac toc, cac tu, cac tac
ve cac » va cac, vien cac

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 ((ky dang) or (ky danh)) xa hoi. hieu ve cac tuc van ((hanh hai) OR (hang hai)) va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ((ky dang) OR (ky danh)) xa hoi. hieu ve cac tuc van ((hanh hai) OR (hang hai)) va triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ((ky dang) or (ky danh)) xa hoi. hieu ve cac tuc van ((hanh hai) OR (hang hai)) va triet".
• Adding a wildcard symbol may retrieve word variants: thu sach ((ky dang) or (ky danh)) xa hoi. hieu ve cac tuc van ((hanh hai) OR (hang hai)) va triet*.