Perhaps you should try some spelling variations:
khanh dai » thanh dat, khanh van, phan dai
cua viet » ca viet, hoa viet, cua vat
thu sach » thuat sach, thuoc sach, thu hoach
xa khanh » xa thanh, van khanh, dat khanh
nam thuc » nam thuoc, am thuc, nam thu
hieu van » hieu va, thien van, lieu va
cam tuc » cam xuc, cam tu, dam thuc
tu sach » su sach, te sach, tu cach
nang ma » tang ma, sang ma, nang cao
ma hoi » mai hoi, xa hoi, ma hoa

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) or (thu sach)) ky nang ma hoi. hieu van ((cam tuc) OR (nam thuc)) xa khanh dai cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) ky nang ma hoi. hieu van ((cam tuc) OR (nam thuc)) xa khanh dai cua viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (thu sach)) ky nang ma hoi. hieu van ((cam tuc) OR (nam thuc)) xa khanh dai cua viet".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thu sach)) ky nang ma hoi. hieu van ((cam tuc) OR (nam thuc)) xa khanh dai cua viet*.