'The Architecture of the City' by Aldo Rossi

'Whereas the humanist conception attempted an integration of subject and object, the modernist conception polemically attempted their separation. The problematic nature of the practice of modern architecture with respect to the theory of modernism has to do precisely with its inability to effect this separation and thus its contamination with imperatives from the humanist conception.'  p.5

'Rather, history becomes analogous to a "skeleton" whose condition serves as a measure of time and, in turn, is measure by time. It is skeleton which bears the imprint of the actions that have taken place and will take a place in the city.' p.5

'The two main permanences in the city are housing and monuments. With respect to the first, Rossi distinguishes between housing and individual houses. Housing is a permanence in the city while individual houses are not; thus, a residential district in the city may persist as such over many centuries, while individual houses within a district will tend to change. With respect to monuments, the relationship is the opposite, for here it is the individual artifact that persists in the city.' p.6

'Urban studies never attribute sufficient importance to research dealing with singular urban artifacts. By ignoring them - precisely those aspects of reality that are most individual, particular, irregular, and also most interesting - we end up constructing theories as artificial as they are useless.' p.21

'Le Corbusier; Ideas and forms' by William J R Curtis

Le Corbusier certainly is a key figure in 20th Century Architecture. He was a visionary whose ideas and projects left deep traces in the history and had a long lasting yet controversial impact on the future development of architecture and the society it was created for.
"Le Corbusier: ideas and forms" is an extensive documentary on his philosophy, urban visions and realised architecture. Here are some interesting quotes from this book.

'Although he never constructed his ideal city in toto, he did treat individual buildings as demonstrations of urbanistic ideas.' p.8 

'He tried to abstract principles from tradition, and to distil these into a formal system with its own rules of appropriateness.' p.8

'Le Corbusier worked from general to particular and from particular to general when solving problems.' p.11

Influences

About Carthusian monastery near Galluzo he wrote:
'Yesterday I went to see Chartreuse... there I found a unique solution to workers' housing. But it will be difficult to duplicate the landscape. oh those monks, what lucky fellows.' p. 22

'Many of the ideas were derived from Camillo Sitte's Der Stadtbau of 1889, which had stressed the need for intimate complexity in the placement of buildings, squares and streets, and which had been heavily illustrated with examples from medieval Italy.' p.30

'The Uses of Disorder. Personal Identity and City Life' by Richard Sennet

I discovered distinctive sociologist and urbanist Richard Sennett by clicking phrase "Open city" in Google. Where this phrase came from I do not remember but it was the name of a lecture given by him at the Harvard GSD which grasped my attention. I found his ideas explicitly simple and persuasive. They are rooted in Humanistic thinking and address such fundamental issues of humankind as craftsmanship, cooperation and urban environment.
"The Uses of Disorder" is one of his earliest works which casts doubts on the ideals of rigid, excessively ordered society. 
Richard Sennett denies purified community where the development of its members is locked into framed identity. Instead, he proposes an alternative environment where otherness, diversity and ambiguity are allowed.
Further are some interesting quotes feeding my concepts and leading deeper into serendipity.

'One technique of planning large human settlements developed in the past hundred years has been the device of establishing "projective needs". This means guessing the future physical and social requirements  of a community or city and then basing present spending and energy so as to achieve a readiness for the projected future state.' p.6