Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
va trien » va truyen, va thiet, va tuyen
ban hanh » ban hang
nhan luc » nang luc
tu tieng » luc tieng, tu tuong, tu trong
tay lang » tai lang, tay tang, tay quang
hieu va » lieu va, hieu qua
luc ban » duc ban, cuc ban, luc bat
ty lang » ty xang, ty hang, tu lang
va nhan » van nhan, ca nhan, va phan

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach ((ty lang) or (tay lang)) xa hoi. hieu va nhan luc ban hanh vi ((va trien) or (tu tieng))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ((ty lang) OR (tay lang)) xa hoi. hieu va nhan luc ban hanh vi ((va trien) OR (tu tieng)).
• Adding a wildcard symbol may retrieve word variants: thu sach ((ty lang) or (tay lang)) xa hoi. hieu va nhan luc ban hanh vi ((va trien) or (tu tieng))*.