Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
hieu vien » hieu hien, hieu viec, thieu nien
vien cay » vien cac, vien cao, vien xay
cay thuc » cay thuoc, can thuc, day thuc
su sach » so sach, vu sach
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
nang xa » nang x, lang xa, nang ma
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: su sach ty nang xa hoi. hieu vien cay thuc ((van ban) or (van thanh)) ((vi cua) OR (di cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ty nang xa hoi. hieu vien cay thuc ((van ban) OR (van thanh)) ((vi cua) OR (di cua)) tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ty nang xa hoi. hieu vien cay thuc ((van ban) or (van thanh)) ((vi cua) OR (di cua)) tre*".