Simhasanadvatrimshika 9.6

9.6

guruśuśrūṣayā vidyā puṣkalena dhanena vā;
athavā vidyayā vidyā, caturthaṃ no 'palabhyate. || 6 ||

Learning [is acquired] by serving the guru, or by abundant wealth,
or else by learning [in exchange for] learning; a fourth [way] is not found. || 6