“…On the other hand, anisotropic type problems in the subcritical case have received specific attention in recent decades. We refer the reader to the papers Boureanu et al [23,43], Fan [44], Ji [45], Mihǎilescu et al [46,47], Ourraoui and Ragusa [48], and Rǎdulescu and Repovš [49], and the references therein.…”