Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
thu sach » thuat sach, thuoc sach, thu hoach
va danh » va dinh, va dan, va hanh
truc va » thuc va, thuc vat, trung va
van cau » van dau, van hau, van chat
tu sach » su sach, te sach, tu cach
lang xa » lang ha, dang xay, lang van
ky lang » ky nang, ky dang, ky tang
vi cua » vai cua
di cua » dai cua, doi cua, de 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 sach) OR (thu sach)) ky lang xa hoi. hieu van cau truc va danh ((vi cua) or (di cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) ky lang xa hoi. hieu van cau truc va danh ((vi cua) OR (di cua)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (thu sach)) ky lang xa hoi. hieu van cau truc va danh ((vi cua) or (di cua)) tre".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (thu sach)) ky lang xa hoi. hieu van cau truc va danh ((vi cua) or (di cua)) tre*.