Perhaps you should try some spelling variations:
sach tren » sach tien, sach tranh
cach thuc » anh thuc, cac thu
thien van » thi van
va triet » va thiet, va trien, ve triet
va tinh » may tinh
va dinh » van dinh, va kinh, vu dinh
lam xuc » cam xuc, lam duoc
van lam » van nam
nano o » nano 1, nano cuo, nano mot
van va » van vat, van van, ban va
o hoc » co hoc, mo hoc, so hoc

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 tren) or (cach thuc)) nano o hoc. thien van lam xuc ((va dinh) OR (va tinh)) van va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach tren) OR (cach thuc)) nano o hoc. thien van lam xuc ((va dinh) OR (va tinh)) van va triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach tren) or (cach thuc)) nano o hoc. thien van lam xuc ((va dinh) OR (va tinh)) van va triet".
• Adding a wildcard symbol may retrieve word variants: tu ((sach tren) or (cach thuc)) nano o hoc. thien van lam xuc ((va dinh) OR (va tinh)) van va triet*.