Perhaps you should try some spelling variations:
cam truc » cau truc, nam truc, lam truoc
truc van » truc va, thuc van, truc ban
van hanh » van thanh, ban hanh, van anh
va triet » va thiet, va trien, ve triet
te sach » toc sach
hieu ve » hieu va, hieu van
cua tre » cua te, cuu tre, cua triet
y lang » o lang, tay lang, yen lang
_ lang » o lang, _ land
ve cam » ve cham, ve cac, va cam

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach ((y lang) or (_ lang)) xa hoi. hieu ve cam truc van hanh vi ((cua tre) or (va triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ((y lang) OR (_ lang)) xa hoi. hieu ve cam truc van hanh vi ((cua tre) OR (va triet)).
• Adding a wildcard symbol may retrieve word variants: te sach ((y lang) or (_ lang)) xa hoi. hieu ve cam truc van hanh vi ((cua tre) or (va triet))*.