Perhaps you should try some spelling variations:
lang thai » lang chai, dang thai, lang hai
su triet » su viet, su tien, ve triet
sach ty » sach y, sach tu, sach thu
thai su » thai xu, tai su, thap su
thue va » thuc va, thuyet va, thuc vat
tu sach » thu sach, su sach, te sach
hieu va » lieu va, hieu qua
nang xa » lang xa, nang ma, mang xa
thu va » thuc va, tu va, thu ha
va cam » va cham, va cac, va cao

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 ty ((nang xa) OR (nang x)) hoi. hieu va cam ((thu va) or (thue va)) lang thai su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty ((nang xa) OR (nang x)) hoi. hieu va cam ((thu va) OR (thue va)) lang thai su triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ty ((nang xa) OR (nang x)) hoi. hieu va cam ((thu va) or (thue va)) lang thai su triet".
• Adding a wildcard symbol may retrieve word variants: tu sach ty ((nang xa) OR (nang x)) hoi. hieu va cam ((thu va) or (thue va)) lang thai su triet*.