Perhaps you should try some spelling variations:
sau tien » dau tien, su tien, cau tieng
loai sau » loai san, loai su, loai sach
dan loai » dang loai, phan loai, nhan loai
hieu ve » hieu va, hieu van
truc va » thuc vat, trung va
thuc va » thuc vat, thuc dan, thuc day
ky lang » ky dang, ky tang, tay lang
tu sach » thu sach, su sach, te sach
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: tu sach ((ky lang) or (ky nang)) xa hoi. hieu ve cam ((truc va) OR (thuc va)) dan loai sau tien~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ky lang) OR (ky nang)) xa hoi. hieu ve cam ((truc va) OR (thuc va)) dan loai sau tien.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((ky lang) or (ky nang)) xa hoi. hieu ve cam ((truc va) OR (thuc va)) dan loai sau tien".
• Adding a wildcard symbol may retrieve word variants: tu sach ((ky lang) or (ky nang)) xa hoi. hieu ve cam ((truc va) OR (thuc va)) dan loai sau tien*.