If time is limited, one must deeply, repeatedly read, contemplate, and observe the Four Agamas and the texts included in the over 70 sutras, vinayas, and sastras of the three compilations of the Zangyao (Essentials of the Tripitaka) published by the Jinling Scriptural Press.
Buddhadharma originally did not divide into schools. Except for the twenty schools of the Sthaviranikaya (see Commentary on the Treatise on the Wheel of the Doctrines of Different Schools by Kuiji), the debate between Emptiness and Existence in India only began with Bhaviveka and Dharmapala. However, regarding the Dharmalaksana Yogacara school, Tripitaka Master Xuanzang composed the Huizong Lun (Treatise Harmonizing the Schools) in 3,000 verses in India, harmonizing the views of the schools of Emptiness and Existence (the Huizong Lun is now lost, and its fragments can only be gleaned from the works of Kuiji, Huizhao, etc.), and formulated the "Inference of True Consciousness-Only" (Zhen Weishi Liang), causing Mahayana scholars to marvel and call him "Mahayanadeva" (Deity of the Mahayana), while the Sthaviranikaya praised him as "Moksadeva" (Deity of Liberation). Aside from inheriting the ultimate teachings—the Three Periods of Teachings—propagated by our fundamental teacher Sakyamuni in the Samdhinirmocana Sutra, the doctrine of Consciousness-Only without external objects can be found in many sutras. Additionally, one can truly understand the doctrines of the Dharmalaksana Yogacara school through the lineage transmitted from Maitreya, Asanga, Vasubandhu, Dignaga, Dharmapala, Silabhadra, Xuanzang, Kuiji, Huizhao, Zhizhou, and Ruli.
For modern scholars who wish to delve deeper, several books are generally recommended for reference. If one has the time, the three compilations of the Zangyao edited by Ouyang Jingwu (published by Xinwenfeng Publishing, Shanghai Bookstore; the Shanghai Bookstore edition was out of print but reprinted in 2015), which collate various sutras using Sanskrit, Chinese, and Tibetan texts, can also be read:
Beginner:
. Shiyi Liang (Ten Meanings Inference): Han Qingjing
. Yogacarabhumi-sastra-vyakhya (By Jinaputra and other Bodhisattvas): Taisho Tripitaka (30)
. Direct Explanation of the Thirty Verses on Consciousness-Only: Sramana Zhixu (Ouyi)
. Supplementary Annotations on the Rules of the Eight Consciousnesses (Supplemented by Master Putai of Lu'an, Ming Dynasty): Taisho Tripitaka (45)
. Weishi Fangyu (Corners of Consciousness-Only): Luo Shixian
. Prefaces to the Sutras and Treatises in the Zangyao: Ouyang Jingwu
. Complete Buddhist Works of Lü Cheng: (Qilu Press, Jinan, Shandong Province; Daqian Publishing, Taiwan)
Intermediate:
. Essentials of Contemplating the Mind in the Cheng Weishi Lun: Sramana Zhixu (Ouyi)
. Weishi Kaimeng Wenda (Q&A for Beginners in Yogacara): Compiled by Master Yunfeng, Yuan Dynasty
. Zhen Xianshi Lun (Treatise on True Reality): Master Taixu
. Vajracchedika-sutra-sastra: Asanga Bodhisattva, Taisho Tripitaka (25)
. Vajracchedika-sutra-sastra (Another version): Vasubandhu Bodhisattva, Taisho Tripitaka (25)
. Vajracchedika-prajnaparamita-sutra-sastra-vyakhya: Verses by Asanga, explanation by Vasubandhu, Taisho Tripitaka (25)
. Dasheng Rudao Cidi (Stages of Entering the Mahayana Path): Zhizhou, Taisho Tripitaka (45)
. Dasabhumika-sutra-sastra: Vasubandhu Bodhisattva: Taisho Tripitaka (26)
. Buddhabhumi-sutra-sastra, Bandhuprabha and other Bodhisattvas: Taisho Tripitaka (26)
. Nine Translated Works on Maitreya Studies: Han Jingqing (Translated from Tibetan into Chinese)
Advanced:
. Taisho Tripitaka (30):
Yogacarabhumi-sastra (Read in conjunction with Han Qingjing's Pixun Ji, as well as Master Kuiji's Brief Compilation on the Yogacarabhumi in Taisho 43, and Master Dunlun's Yogacarabhumi Record in Taisho 42.)
. Taisho Tripitaka (31) Complete:
Such as: Cheng Weishi Lun (Synthesized by Tripitaka Master Xuanzang from the Ten Great Masters of India), Ratnagotravibhaga (Uttaratantra)
. Taisho Tripitaka (32) Complete:
Such as: Nyayamukha, Nyayamukha (another version), Nyayapravesa, Tarka-sastra, Treatise on Generating Bodhicitta, Treatise on Generating Bodhicitta Free from Characteristics
. Taisho Tripitaka (43) Complete.
. Taisho Tripitaka (44) Complete:
Such as: Commentary on the Madhyantavibhaga (Kuiji), Commentary on the Nyayapravesa (Great Commentary on Hetuvidya, Kuiji), Yiduan on Hetuvidya (Huizhao), Zuanya on the Nyayapravesa (Huizhao)
. Taisho Tripitaka (45):
Dasheng Fayuan Yilin Zhang (Kuiji), Collection on Encouraging the Generation of Bodhicitta (Huizhao), Treatise of the Wisdom Sun Revealing the Middle and the Extremes (Huizhao)
. Cheng Weishi Lun Shuyi (Wings to the Commentary on the Cheng Weishi Lun): Han Jingqing
. Manji Zokuzokyo (Manji Extended Tripitaka):
. Volumes 77, 78, 79, 80, 81, 82, 83, 84 (Including various masters' records on the Abhidharmakosa, Cheng Weishi Lun, and commentaries on the Nyayapravesa)
Additional Supplement:
. Works by Japanese Masters, such as:
Taisho Tripitaka (66):
Yuishikiron Dōgakushō (Records of Fellow Students on the Vijnaptimatra Treatise)
Taisho Tripitaka (71):
Daijō Hossō Gensinshō (Deep Exploration of Mahayana Dharmalaksana), Kanjin Kakumushō (Awakening from Dreams through Mind Contemplation), Ryakujutsu Hossōgi (Brief Explanation of Dharmalaksana Doctrines), Daijō Hōon Girinshō Shishikushō (Lion's Roar Commentary on the Yilin Zhang), Shichijūgohō Myōmoku (Names of the Seventy-Five Dharmas - Sarvastivada, based on the Abhidharmakosa), Ushū Shichijūgohōki (Record of the Seventy-Five Dharmas of the Existence School)