Perhaps you should try some spelling variations:
lang chai » lang ha, lang cua, lang phi
lang thai » dang thai, lang hai, hoang thai
ve triet » va trien, su triet
tu sach » thu sach, su sach, te sach
hieu va » lieu va, hieu qua
ty hang » ly hang, ty xang, thi hang
ty nang » ky nang, ty xang, ly nang
thu va » thuc va, thue va, tu va
va nam » van nam, ha nam, va nay

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 nang) OR (ty hang)) xa hoi. hieu va nam thu va ((lang thai) or (lang chai)) ve triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ty nang) OR (ty hang)) xa hoi. hieu va nam thu va ((lang thai) OR (lang chai)) ve triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((ty nang) OR (ty hang)) xa hoi. hieu va nam thu va ((lang thai) or (lang chai)) ve triet".
• Adding a wildcard symbol may retrieve word variants: tu sach ((ty nang) OR (ty hang)) xa hoi. hieu va nam thu va ((lang thai) or (lang chai)) ve triet*.