[rramadass]

Though not specific to C language, C.A.R Hoare's Retrospective: An Axiomatic Basis for Computer Programming provides insight on why Software is so reliable in spite of a lack of application of formal verification methods.

Retrospective: https://cacm.acm.org/opinion/retrospective-an-axiomatic-basi...

Here is a pdf of the retrospective along with the original paper : https://harrymoreno.com/assets/greatPapersInCompSci/2.2_-_An...

[Jtsummers]

Here is another paper of his related to this:

How Did Software Get So Reliable Without Proof? C.A.R. Hoare 1996 (?) http://users.csc.calpoly.edu/~gfisher/classes/509/handouts/h...