Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
danh doi » danh di, thanh doi, dung doi
ve triet » va trien, su triet
ky tang » ky nang, ky dang, kho tang
van hoc » van hoa
truc va » thuc va, thuc vat, trung va
va danh » va dinh, va dan, va hanh
ky lang » ky nang, ky dang, tay lang
van cac » van hac, van cau, van bac
doi ve » moi ve, doi va, noi ve

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuoc sach ((ky lang) OR (ky tang)) xa hoi. hieu ((van cac) or (van hoc)) truc va danh doi ve triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuoc sach ((ky lang) OR (ky tang)) xa hoi. hieu ((van cac) OR (van hoc)) truc va danh doi ve triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuoc sach ((ky lang) OR (ky tang)) xa hoi. hieu ((van cac) or (van hoc)) truc va danh doi ve triet".
• Adding a wildcard symbol may retrieve word variants: thuoc sach ((ky lang) OR (ky tang)) xa hoi. hieu ((van cac) or (van hoc)) truc va danh doi ve triet*.