Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hanh tai » thanh tai, hang tai, han tai
hieu ve » hieu va, hieu van
cuc tre » duc tre, cua tre, cuu tre
lang xa » lang ha, dang xay, lang van
ky lang » ky nang, ky dang, ky tang
so sanh » do sanh
tuc va » thuc va, truc va, tuc xa
luc va » duc va, loc va
ve cam » ve cham, ve cac, va cam

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((toc sach) or (so sanh)) ky lang xa hoi. hieu ve cam ((tuc va) or (luc va)) hanh tai cuc tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (so sanh)) ky lang xa hoi. hieu ve cam ((tuc va) OR (luc va)) hanh tai cuc tre.
• Adding a wildcard symbol may retrieve word variants: ((toc sach) or (so sanh)) ky lang xa hoi. hieu ve cam ((tuc va) or (luc va)) hanh tai cuc tre*.