Perhaps you should try some spelling variations:
nang hoc » nang doc, nang luc, dong hoc
duc manh » suc manh, duc anh, duc minh
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
hoc hai » hoc dai, hoc bai, hoc tai
hieu ve » hieu va, hieu van
cuc ban » cua ban, cac ban, cuu ban
duc van » duc va, duc tan, duc phan
van tai » von tai, van tuan
cuc tre » duc tre, cua tre, cuu tre
ve cac » va cac, vien 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 sach ky nang hoc hai. hieu ve cac ((cuc ban) or (((duc van) or (duc manh)))) van tai cuc tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky nang hoc hai. hieu ve cac ((cuc ban) OR (((duc van) OR (duc manh)))) van tai cuc tre.
• Adding a wildcard symbol may retrieve word variants: su sach ky nang hoc hai. hieu ve cac ((cuc ban) or (((duc van) or (duc manh)))) van tai cuc tre*.