Perhaps you should try some spelling variations:
va trien » va truyen, va thiet, va tuyen
hang tai » hang va, dung tai
tang mai » tang tai, lang mai, sang mai
va hang » van hang, va nang, va lang
cam tuc » cam tu, nam thuc, dam thuc
sach ky » sac ky, sach y, sach ty
su sach » so sach, vu sach
tang ma » mang may, tang van
hieu va » lieu va, hieu qua
tai va » thai va, mai va, tri va

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 ((tang mai) OR (tang ma)) khoi. hieu va ((cam tuc) or (cam xuc)) va hang tai va trien~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky ((tang mai) OR (tang ma)) khoi. hieu va ((cam tuc) OR (cam xuc)) va hang tai va trien*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky ((tang mai) OR (tang ma)) khoi. hieu va ((cam tuc) or (cam xuc)) va hang tai va trien*".