Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
hieu van » hieu va, thien van, hieu ve
van hanh » van thanh, ban hanh, van anh
van tuan » van quan, van ban, anh tuan
dua tren » dung tren
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
vi dua » vi du, vi dum, vi lua

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 nang xa hoi. ((hieu van) OR (lieu va)) cam xuc ((van hanh) or (van tuan)) vi dua tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky nang xa hoi. ((hieu van) OR (lieu va)) cam xuc ((van hanh) OR (van tuan)) vi dua tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ky nang xa hoi. ((hieu van) OR (lieu va)) cam xuc ((van hanh) or (van tuan)) vi dua tren".
• Adding a wildcard symbol may retrieve word variants: thu sach ky nang xa hoi. ((hieu van) OR (lieu va)) cam xuc ((van hanh) or (van tuan)) vi dua tren*.