Perhaps you should try some spelling variations:
cam truc » cau truc, nam truc, lam truoc
va hanh » van hanh, va thanh, va danh
truc va » thuc va, thuc vat, trung va
hieu ve » hieu va, hieu van
su sach » so sach, vu sach
ma hoi » mai hoi, xa hoi, ma hoa
y nang » ky nang, ly nang, may nang
v nang » va nang, vu nang, van nang
ve cam » ve cham, ve cac, va cam
vi su » va su, ve su, oi su
ki su » ky su

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 va hanh ((vi su) OR (ki su)) 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 va hanh ((vi su) OR (ki su)) 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 va hanh ((vi su) OR (ki su)) triet".
• Adding a wildcard symbol may retrieve word variants: su sach ((y nang) or (v nang)) ma hoi. hieu ve cam truc va hanh ((vi su) OR (ki su)) triet*.