Perhaps you should try some spelling variations:
thu sach » thuat sach, thuoc sach, thu hoach
van hanh » van thanh, ban hanh, van ban
tham hoc » thai hoc, tham hoa, than hoc
cau tren » cu tren, dau tren, ca tren
ty nang » ky nang, ty xang, ty hang
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
tu sach » su sach, te sach, tu cach
van anh » van thanh, tuan anh, van minh
va tham » van tham, va cham, va thanh
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: ((thu sach) or (tu sach)) ty nang xa hoi. hieu va tham hoc ((van hanh) OR (van anh)) vi cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thu sach) OR (tu sach)) ty nang xa hoi. hieu va tham hoc ((van hanh) OR (van anh)) vi cau tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((thu sach) or (tu sach)) ty nang xa hoi. hieu va tham hoc ((van hanh) OR (van anh)) vi cau tren".
• Adding a wildcard symbol may retrieve word variants: ((thu sach) or (tu sach)) ty nang xa hoi. hieu va tham hoc ((van hanh) OR (van anh)) vi cau tren*.