apologies in advance - this may be a very difficult question.
i remember reading instructional books/manuals in the 1970s. the illustrations of the people were very distinct. it’s hard to describe - the people were drawn with alot of black-and-white lines, their faces are very blocky.
another similar example i have seen is on the TTC subway (Toronto). At the college street station there is a mural drawing of Toronto Maple Leaf and Montreal Canadiens players. these murals are drawn in the same fashion as these books i mentioned.
an example is here
is there a name for this type of drawing style? is there any information about where it came from and what happened to it?