Perhaps you should try some spelling variations:
va tuyen » va truyen, tac tuyen, ke tuyen
thuc dan » thuc hanh, hoc dan, thuc vat
hoa lang » hoa dan, hoa van
hieu van » hieu va, thien van, lieu va
va triet » va thiet, va trien, ve triet
sach hoa » sach ha, sach hoi, bach hoa
su sach » so sach, vu sach
thuc va » thuc vat, thuc day
van cam » van nam, van lam, van cau
lang xa » lang ha, dang xay, lang van

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach hoa lang xa hoi. hieu van cam ((thuc va) OR (thuc dan)) hanh vi ((va triet) or (va tuyen))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach hoa lang xa hoi. hieu van cam ((thuc va) OR (thuc dan)) hanh vi ((va triet) OR (va tuyen))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach hoa lang xa hoi. hieu van cam ((thuc va) OR (thuc dan)) hanh vi ((va triet) or (va tuyen))*".