Perhaps you should try some spelling variations:
trong van » trong cac
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
hieu va » lieu va, hieu qua
cam tuc » cam tu, nam thuc, dam thuc
va hanh » van hanh, va thanh, va danh
luu tre » luu tru, cuu tre, luy tre
vi luu » vi lua

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ky ((nang x) or (trong van)) hoi. hieu va ((cam tuc) OR (cam xuc)) va hanh vi luu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky ((nang x) OR (trong van)) hoi. hieu va ((cam tuc) OR (cam xuc)) va hanh vi luu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky ((nang x) or (trong van)) hoi. hieu va ((cam tuc) OR (cam xuc)) va hanh vi luu tre".
• Adding a wildcard symbol may retrieve word variants: su sach ky ((nang x) or (trong van)) hoi. hieu va ((cam tuc) OR (cam xuc)) va hanh vi luu tre*.