... and are partially wrong
Among other errors:
• the White-Freightliner "Conventional" was called WFC, was made from 1974 onwards and became the Freightliner FLC-120 in 1977;
• The Powerliner was unveiled in 1973 (same link).
• No model with a "double square" grille can be younger than 1981, as the diagonal bar grille of the Volvo-White appeared after Volvo bought White in 1980.

Here are just quick corrections, without searching for all models shown. But I'm sure there are some other small mistakes...
autowp.ru is a nice website for factory pictures, but is definitely not a trustworthy source concerning the model years.