Perhaps you should try some spelling variations:
trong dong » trong cong, trong nong, trong dang
hieu tinh » chieu tinh, lieu tinh, hieu binh
kieu tinh » lieu tinh, trieu tinh, diep tinh
trinh cam » trinh cham, trinh cau, trinh cac
trinh tam » trinh tai, trinh toan, trinh cham
dong dan » dong danh, duong dan, dong san
dan phan » doan phan, dan chan, van phan

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

• Performing a fuzzy search may retrieve terms with similar spellings: doc ((hieu tinh) or (kieu tinh)) - hanh ((trinh cam) OR (trinh tam)) trong dong dan phan tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc ((hieu tinh) OR (kieu tinh)) - hanh ((trinh cam) OR (trinh tam)) trong dong dan phan tu*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc ((hieu tinh) or (kieu tinh)) - hanh ((trinh cam) OR (trinh tam)) trong dong dan phan tu*".