Perhaps you should try some spelling variations:
van khanh » van thanh, van hanh, van anh
van khang » van thanh, van quang, van hanh
te sach » toc sach
cam thu » nam thu, cac thu, ca thu
du tren » dua tren, dau tren, duc tren
hieu ve » hieu va, hieu van
nang xa » nang x, lang xa, nang ma
so sanh » do sanh
ve cam » ve cham, ve cac, va cam
di du » li du

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) or (so sanh)) ky nang xa hoi. hieu ve cam thu ((van khang) OR (van khanh)) di du tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (so sanh)) ky nang xa hoi. hieu ve cam thu ((van khang) OR (van khanh)) di du tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) or (so sanh)) ky nang xa hoi. hieu ve cam thu ((van khang) OR (van khanh)) di du tren".
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (so sanh)) ky nang xa hoi. hieu ve cam thu ((van khang) OR (van khanh)) di du tren*.