Perhaps you should try some spelling variations:
cam truc » cau truc, nam truc, lam truoc
dan loai » dang loai, phan loai, nhan loai
sau tien » su tien, cau tieng, sach tien
dau tien » van tien
tu sach » thu sach, su sach, te sach
ky lang » ky dang, ky tang, tay lang
hieu ve » hieu va, hieu van
truc va » thuc va, thuc vat, trung va
ve cam » ve cham, ve cac, va cam
va dan » ca dan, va dao, va dau

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 dan loai ((sau tien) OR (dau 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 dan loai ((sau tien) OR (dau 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 dan loai ((sau tien) OR (dau tien))".
• Adding a wildcard symbol may retrieve word variants: tu sach ((ky lang) or (ky nang)) xa hoi. hieu ve cam truc va dan loai ((sau tien) OR (dau tien))*.