Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
van hanh » van thanh, ban hanh, van anh
sach ky » sac ky, sach y, sach ty
nang ma » tang ma, sang ma, nang cao
hieu ve » hieu va, hieu van
cao suc » cao duc
ma hoi » mai hoi, xa hoi, ma hoa
di cua » doi cua, de cua, do cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuat sach ky nang ma hoi. hieu ve ((cao suc) or (cao su)) van hanh ((di cua) OR (dai cua)) te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuat sach ky nang ma hoi. hieu ve ((cao suc) OR (cao su)) van hanh ((di cua) OR (dai cua)) te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuat sach ky nang ma hoi. hieu ve ((cao suc) or (cao su)) van hanh ((di cua) OR (dai cua)) te".
• Adding a wildcard symbol may retrieve word variants: thuat sach ky nang ma hoi. hieu ve ((cao suc) or (cao su)) van hanh ((di cua) OR (dai cua)) te*.