Perhaps you should try some spelling variations:
thang doi » thang loi, hang doi, thanh doi
van thang » van thanh, van khang, van hang
thuc van » thuc vat, thuc dan, thuc va
sach ky » sac ky, sach ty, sach kem
su viet » so viet
lang xa » lang ha, dang xay, lang van
he nam » ha nam, nghe nam
doi su » oi su, don su, voi su
ve nam » va nam, le nam, te nam

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 ky) or (sach y)) lang xa hoi. hieu ((ve nam) OR (he nam)) thuc van thang doi su viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach ky) OR (sach y)) lang xa hoi. hieu ((ve nam) OR (he nam)) thuc van thang doi su viet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach ky) or (sach y)) lang xa hoi. hieu ((ve nam) OR (he nam)) thuc van thang doi su viet*".