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