Perhaps you should try some spelling variations:
van tham » van thanh, van tuan, van tai
van hanh » van thanh, ban hanh, van anh
van chat » cao chat
hanh ki » hanh vi, hanh ky, hanh kien
duc van » duc va, duc tan, duc manh
su viet » so viet
nang xa » nang x, lang xa, nang ma
sach ty » sach y, sach tu, sach thu
sac ky » cac ky, sai ky
ki su » ky su

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu ((sac ky) or (sach ty)) nang xa hoi. hieu ((van tham) OR (van chat)) duc van hanh ki su viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sac ky) OR (sach ty)) nang xa hoi. hieu ((van tham) OR (van chat)) duc van hanh ki su viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sac ky) or (sach ty)) nang xa hoi. hieu ((van tham) OR (van chat)) duc van hanh ki su viet".
• Adding a wildcard symbol may retrieve word variants: tu ((sac ky) or (sach ty)) nang xa hoi. hieu ((van tham) OR (van chat)) duc van hanh ki su viet*.