Perhaps you should try some spelling variations:
nang chat » nang phat, nang cham, nang cao
chat hoc » chat hoa, chat thom, cho hoc
thuc va » thuc vat, thuc dan, thuc day
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
ve cham » va cham, ve chat, vu cham
hieu ve » hieu va, hieu van
tuc va » truc va, tuc xa, duc va
va va » va vua, va vai, va vat

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 ky nang chat hoc. hieu ve cham ((tuc va) or (thuc va)) hanh ((va va) OR (va van)) thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang chat hoc. hieu ve cham ((tuc va) OR (thuc va)) hanh ((va va) OR (va van)) thiet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang chat hoc. hieu ve cham ((tuc va) or (thuc va)) hanh ((va va) OR (va van)) thiet".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang chat hoc. hieu ve cham ((tuc va) or (thuc va)) hanh ((va va) OR (va van)) thiet*.