Perhaps you should try some spelling variations:
luan phan » luan van, luan hoan
ham luan » pham luan, han luan, phap luan
dang vat » dang van, dong vat, dang nhat
cau tren » cu tren, dau tren, ca tren
hieu ve » hieu va, hieu van
nang xa » nang x, lang xa, nang ma
sach ty » sach y, sach tu, sach thu
dang va » dang van, dung va, dong va
ty nang » ky nang, ty xang, ty hang
tu sach » thu sach, su sach, te sach
ve ham » ve cham, le ham, ve am

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ty nang xa hoi. hieu ve ham luan phan ((((dang va) OR (dang vat))) or (hang va)) cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty nang xa hoi. hieu ve ham luan phan ((((dang va) OR (dang vat))) OR (hang va)) cau tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ty nang xa hoi. hieu ve ham luan phan ((((dang va) OR (dang vat))) or (hang va)) cau tren".
• Adding a wildcard symbol may retrieve word variants: tu sach ty nang xa hoi. hieu ve ham luan phan ((((dang va) OR (dang vat))) or (hang va)) cau tren*.