Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
van hanh » van thanh, ban hanh, van anh
su sach » so sach, vu sach
ky lang » ky dang, ky tang, tay lang
van cam » van nam, van lam, van cau
cam hoc » cao hoc, am hoc, cam hoa
hoc van » hoc dan, hoc va, hoc vat
vai cua » dai cua, hai cua, lai cua
vi cua » di cua

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 lang) OR (ky nang)) xa hoi. hieu van cam hoc van hanh ((vi cua) or (vai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((ky lang) OR (ky nang)) xa hoi. hieu van cam hoc van hanh ((vi cua) OR (vai cua)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ((ky lang) OR (ky nang)) xa hoi. hieu van cam hoc van hanh ((vi cua) or (vai cua)) tre".
• Adding a wildcard symbol may retrieve word variants: su sach ((ky lang) OR (ky nang)) xa hoi. hieu van cam hoc van hanh ((vi cua) or (vai cua)) tre*.