Perhaps you should try some spelling variations:
tang van » dang van, hoang van, trong van
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
hieu va » lieu va, hieu qua
luu tre » luu tru, cuu tre, luy tre
va cam » va cham, va cac, va cao
tuc va » thuc va, truc va, duc va
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 (tang van)) hoi. hieu va cam ((tuc va) OR (tuc xa)) hanh vi luu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky ((nang x) OR (tang van)) hoi. hieu va cam ((tuc va) OR (tuc xa)) hanh vi luu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky ((nang x) or (tang van)) hoi. hieu va cam ((tuc va) OR (tuc xa)) hanh vi luu tre".
• Adding a wildcard symbol may retrieve word variants: su sach ky ((nang x) or (tang van)) hoi. hieu va cam ((tuc va) OR (tuc xa)) hanh vi luu tre*.