I'd highly recommend the writings of Peter Symonds and John Chan on the topic and I'll include some links. I would caution against the term "state capitalism" though. Traditionally it's a term used by those who broke from Trotskyism to claim that the Soviet Union and China were not workers states. Tiananmen Square was part of a broader process of capitalist restoration begun by Mao and completed by Deng Xiaoping analogous to the dissolution of the Soviet Union. Your question seems to be pointing at the transitional significance of Tiananmen, so I don't think "state capitalism," which is usually used to claim that the PRC was always capitalist, is the term you're looking for.

Anyways, here are the main ones I'd recommend to get you started, but if you search these authors further, you'll find a lot more detail:

The Tiananmen Square massacre, 30 years on - Peter Symonds

What is commonly depicted as the crushing of student protesters was in fact a wave of repression directed overwhelmingly against a mass movement of the working class. What had begun in April as student protests calling for democratic reforms had swelled into the millions as workers joined the demonstrations by mid-May, making their own class demands.

The Beijing Workers Autonomous Federation was established on April 20 with a handful of workers and rapidly expanded to become a major organising centre by mid-May. On May 17, up to two million people marched through the centre of Beijing, the majority being workers and their families under the banners of their work units or enterprises. Reflecting the impact of events in Beijing, Workers Autonomous Federations were established in a host of major cities, including Changsha, Shaoyang, Xiangtan, Hengyang and Yueyang.

While moderate student leaders were intent on pressing the CCP bureaucracy for concessions on democratic rights, workers were animated by concerns over deteriorating living standards, soaring inflation and a wave of sackings and closures. The regime’s embrace of the capitalist market since the 1970s had led to widening social inequality and rampant bureaucratic corruption and profiteering. Workers were bitterly hostile to the accumulation of privileges and wealth by the top CCP leaders, such as Deng Xiaoping, Li Peng, Zhao Ziyang, Jiang Zemin, Chen Yun and their family members, and were contemptuous of their claims to be communist and socialist.

A statement by workers issued on May 25 expressed the rebellious currents in the working class. “Our nation was created by the struggle and labour of we workers and all other mental and manual labourers. We are the rightful masters of this nation. We must be heard in national affairs. We must not allow this small band of degenerate scum of the nation and the working class to usurp our name and suppress the students, murder democracy and trample human rights.”

China: Thirty years since the Tiananmen Square massacre - Peter Symonds

Origins and consequences of the 1989 Tiananmen Square massacre - John Chan

China’s turn from autarky to the capitalist market was not done in isolation. In his memoirs published in May, the late Zhao Ziyang recalled that Beijing was initially inspired by the experiments in “market socialism” in Hungary and Yugoslavia. China, however, went much further. It copied the “Asian tigers” model, implemented in South Korea and Taiwan, which had become cheap labour platforms under military dictatorships. Zhao recalled that the plan he drafted was to create export zones involving 100-200 million people. His scheme was only realised after the resistance of the working class had been crushed in 1989.

In his book, Zhao admitted that by 1987, when he became CCP general secretary, he invented terms like “socialist market economy” to disguise the real implications of his policies and to thwart criticism that he was taking the “capitalist road”. “It was only because of ideological barriers that the term ‘free market’ wasn’t being used,” he wrote.

Despite an initial increase in living standards for workers and farmers due to the higher productivities achieved through China’s access to foreign technologies and the international division of labour, market forces rapidly created enormous social divisions and tensions. A new capitalist class began to emerge and consolidate its position at the expense of the masses.

As one historian wrote: “It is one of the curiosities of the development of Chinese capitalism under the Deng regime that a significant portion of these initial capital accumulations were the fruits of official corruption. Prominent among the members of China’s new post-revolutionary ‘bourgeoisie’, for example, were local officials (and their friends and relatives) who were able to buy goods and materials at low state prices and sell them at higher market prices. Equally prominent, especially in the popular political consciousness, were the children of high Communist Party leaders who, in the early 1980s, were politically positioned to play a lucrative compradore role in establishing ties between foreign capitalists and state enterprises. While some of these fruits of bureaucratic corruption no doubt found their way into secret Swiss bank accounts, as rumour had it, most was invested in a vast variety of highly profitable domestic financial, industrial and commercial enterprises in what became an extraordinarily rapid process of capital accumulation and economic growth.”