Perhaps you should try some spelling variations:
thien van » thi van
thu sach » tu sach, thuat sach, thuoc sach
sach thi » sach thu, sach tai, sach thieu
thi nang » thi cong, ki nang, thi hanh
hieu van » lieu va, hieu ve
tinh lap » trinh lap, tinh lao, dinh lap
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
cac day » cac dan, cac dai, cac cay
va tinh » may tinh
ca viet » va viet, co viet, hoa viet
lap ca » lap cua, lap va, lap da

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach thi nang xa hoi. ((((hieu van) OR (thien van))) or (hieu va)) cac day va tinh lap ca viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach thi nang xa hoi. ((((hieu van) OR (thien van))) OR (hieu va)) cac day va tinh lap ca viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach thi nang xa hoi. ((((hieu van) OR (thien van))) or (hieu va)) cac day va tinh lap ca viet".
• Adding a wildcard symbol may retrieve word variants: thu sach thi nang xa hoi. ((((hieu van) OR (thien van))) or (hieu va)) cac day va tinh lap ca viet*.