My opinion hasn't been well thought out and is only for your reference.
我的意见很不成熟，只是供你参考。
《新英汉大辞典》
2
You should keep the book well for future reference.
你该把这本书收好，以便将来作为参考。
3
Get into the habit of asking for a letter of reference from someone who you have worked with who might be moving on and ask that person if they would be willing to serve as a verbal reference as well.