Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
duc manh » suc manh, duc anh, duc minh
ky lang » ky nang, ky dang, ky tang
lang ha » long ha
hieu ve » hieu va, hieu van
ve giao » te giao, viet giao, van giao
duc van » duc va, duc tan, duc phan
vi cua » vai cua, di cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu cac) or (thu sach)) ky lang ha noi. hieu ve giao ((duc van) OR (duc manh)) hanh vi cua vat~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu cac) OR (thu sach)) ky lang ha noi. hieu ve giao ((duc van) OR (duc manh)) hanh vi cua vat.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu cac) or (thu sach)) ky lang ha noi. hieu ve giao ((duc van) OR (duc manh)) hanh vi cua vat".
• Adding a wildcard symbol may retrieve word variants: ((tu cac) or (thu sach)) ky lang ha noi. hieu ve giao ((duc van) OR (duc manh)) hanh vi cua vat*.