Perhaps you should try some spelling variations:
sach nuoc » sach duoc, cac nuoc, bach tuoc
tinh vai » tinh va, tinh hai, tinh bai
thu nang » thi nang, thu hang, thu bang
man tinh » may tinh, ban tinh, quan tinh
hieu van » hieu va, thien van, lieu va
bac nuoc » cac nuoc, bach tuoc, hoc nuoc
tu sach » thu sach, su sach, tu cach
vai cua » dai cua, hai cua, lai cua
nang xa » nang x, lang xa, nang ma
te sach » toc sach
cua te » cua tu

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) or (te sach)) thu nang xa hoi. hieu van ((bac nuoc) OR (sach nuoc)) man tinh vai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (te sach)) thu nang xa hoi. hieu van ((bac nuoc) OR (sach nuoc)) man tinh vai cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (te sach)) thu nang xa hoi. hieu van ((bac nuoc) OR (sach nuoc)) man tinh vai cua te".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (te sach)) thu nang xa hoi. hieu van ((bac nuoc) OR (sach nuoc)) man tinh vai cua te*.