Perhaps you should try some spelling variations:
ve triet » va trien
su triet » su viet, su tien
van hanh » van thanh, ban hanh, van anh
truc van » truc va, thuc van, truc ban
cam truc » cau truc, nam truc, lam truoc
su sach » so sach, vu sach
hieu ve » hieu va, hieu van
y nang » ky nang, ly nang, may nang
ma hoi » mai hoi, xa hoi, ma hoa
v nang » va nang, vu nang, van nang
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: su sach ((y nang) or (v nang)) ma hoi. hieu ve cam truc van hanh vi ((su triet) OR (ve triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((y nang) OR (v nang)) ma hoi. hieu ve cam truc van hanh vi ((su triet) OR (ve triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ((y nang) or (v nang)) ma hoi. hieu ve cam truc van hanh vi ((su triet) OR (ve triet))".
• Adding a wildcard symbol may retrieve word variants: su sach ((y nang) or (v nang)) ma hoi. hieu ve cam truc van hanh vi ((su triet) OR (ve triet))*.