Perhaps you should try some spelling variations:
hanh thai » nhanh thai, hanh tai, anh thai
hinh thai » sinh thai, tinh thai, dinh thi
dang hoa » dang hoai, dang khoa, dong hoa
cua tre » cua te, cuu tre, cua triet
hoa hoi » khoa hoi, hoa hoc, hoa doi
hieu ve » hieu va, hieu van
cao duc » dao duc, cao suc, giao duc
duc van » duc va, duc tan, duc manh
sac ky » cac ky
ve cao » va cao, ve bao, ve cac

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

• Performing a fuzzy search may retrieve terms with similar spellings: su ((sai ky) or (sac ky)) dang hoa hoi. hieu ve cao duc van ((hanh thai) OR (hinh thai)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sai ky) OR (sac ky)) dang hoa hoi. hieu ve cao duc van ((hanh thai) OR (hinh thai)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sai ky) or (sac ky)) dang hoa hoi. hieu ve cao duc van ((hanh thai) OR (hinh thai)) cua tre".
• Adding a wildcard symbol may retrieve word variants: su ((sai ky) or (sac ky)) dang hoa hoi. hieu ve cao duc van ((hanh thai) OR (hinh thai)) cua tre*.