Perhaps you should try some spelling variations:
sach tru » sach truc, sach thu, sach tu
tru nang » tra nang, tri nang, truc nano
thai va » thai van
thuc va » thuc vat, thuc dan, thuc day
tu sach » thu sach, su sach, te sach
qua hac » qua hai, qua cac, qua hoat
nang xa » nang x, lang xa, nang ma
tuc va » truc va, tuc xa, duc va
hai va » hai van, hoi va, mai va

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 tru nang xa hoi. hieu qua hac ((tuc va) OR (thuc va)) danh ((hai va) or (thai va)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach tru nang xa hoi. hieu qua hac ((tuc va) OR (thuc va)) danh ((hai va) OR (thai va)) triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach tru nang xa hoi. hieu qua hac ((tuc va) OR (thuc va)) danh ((hai va) or (thai va)) triet".
• Adding a wildcard symbol may retrieve word variants: tu sach tru nang xa hoi. hieu qua hac ((tuc va) OR (thuc va)) danh ((hai va) or (thai va)) triet*.