Perhaps you should try some spelling variations:
thuyet hach » thuyet mach, thuyet xac, thuyet cac
hoc thuyet » hoc chuyen
nhung cong » dung cong, thong cong, hang cong
hanh manh » hanh mang, lanh manh, hoang manh
cua nhung » va nhung
manh cua » doanh cua, ban cua
van tuan » van quan, anh tuan

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc thuyet hach - hanh manh cua nhung cong ((van tuan) or (van ban)) cu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thuyet hach - hanh manh cua nhung cong ((van tuan) OR (van ban)) cu.
• Adding a wildcard symbol may retrieve word variants: hoc thuyet hach - hanh manh cua nhung cong ((van tuan) or (van ban)) cu*.