Perhaps you should try some spelling variations:
thang cong » thanh cong, thang long, thong cong
hoc thieu » hoc hien
cong thuc » cong tac
thuc hang » thuc hanh, thu hang, phuc hang
hang cong » dang cong, hang nong, bang cong
cong lang » cong vang, cong luong, cong quang
lang phan » nang phan, lang thang, lang phong

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((hoc thieu) OR (toc thieu)) sach - thang cong thuc hang cong lang phan tu~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((hoc thieu) OR (toc thieu)) sach - thang cong thuc hang cong lang phan tu".
• Adding a wildcard symbol may retrieve word variants: ((hoc thieu) OR (toc thieu)) sach - thang cong thuc hang cong lang phan tu*.