Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
hieu ve » hieu va, hieu van
cac duc » cac du, cao duc, cac dac
duc van » duc va, duc tan, duc manh
sai ky » sac ky
ve cac » va cac, vien cac
vi cua » vai cua
di cua » dai cua, doi cua, de cua

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