How valid do you think these sources are?

Question

I am writting an essay on the Spring Offensive of World War One and came across this website which offers several sources:
http://www.spartacus.schoolnet.co.uk/FWWspring.htm

How valid do dyou think these sources are?

How can I get more information about the sources to quote them properly?

Do you have any additional sources websites or any kind of input you'd like to volunteer about the Spring Offensive or the Stromtroopers?

This is a serious question, serious answers only please.

Answer 1

Looks well documented. Try to find corroborating evidence in books or newspapers.