Perhaps you should try some spelling variations:
thu sach » thuat sach, thuoc sach, thu hoach
hieu van » hieu va, thien van, lieu va
van hanh » van thanh, ban hanh, van anh
van tuan » van quan, van ban, anh tuan
cau tren » cu tren, dau tren, ca tren
tu sach » su sach, te sach, tu cach
nang xa » nang x, lang xa, nang ma
van cam » van nam, van lam, van cau
vi cau » va cau, ve cau, di cau

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