Perhaps you should try some spelling variations:
cua viet » ca viet, hoa viet, cua vat
xang van » dang van, tang van, nang van
lang van » dang van, tang van, hoang van
sach thu » sach thue, sach thieu, sach tham
cau luc » cau phuc
va hanh » van hanh, va thanh, va danh
so sach » so sanh, bo sach, co sach
hieu va » lieu va, hieu qua
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: so sach thu ((xang van) or (lang van)) hoe. hieu va ((cau luc) OR (cau truc)) va hanh vi cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach thu ((xang van) OR (lang van)) hoe. hieu va ((cau luc) OR (cau truc)) va hanh vi cua viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach thu ((xang van) or (lang van)) hoe. hieu va ((cau luc) OR (cau truc)) va hanh vi cua viet".
• Adding a wildcard symbol may retrieve word variants: so sach thu ((xang van) or (lang van)) hoe. hieu va ((cau luc) OR (cau truc)) va hanh vi cua viet*.