Karma, akarma and vikarma are very clearly described in the Bhagavad-gītā

Karma, akarma and vikarma are very clearly described in the Bhagavad-gītā. 

Actions that are performed in terms of one's prescribed duties, as mentioned in the revealed scriptures, are called karma. 

Actions that free one from the cycle of birth and death are called akarma. 

And actions that are performed through the misuse of one's freedom and that direct one to the lower life forms are calledvikarma. 

Of these three types of action, that which frees one from the bondage to karma is preferred by intelligent men. Ordinary men wish to perform good work in order to be recognized and achieve some higher status of life in this world or in heaven, but more advanced men want to be free altogether from the actions and reactions of work. 
(Sri isopanishad).

Ugra-karma means ferocious activities.
(Lecture on Srimad Bhagavatam---6:1:52).

Karma-yoga means just to dovetail your karma with yoga principles to arrive to the bhakti-yoga.
(Lecture on Bhagavad-Gita---4:1 ).

When a person knows the goal of life but is addicted to the fruits of activities, he is acting in karma-yoga.
(Bhagavad-Gita----10:10----purport).

There is a difference between karma and karma-yoga. Karma is regulated action for the enjoyment of the fruit by the performer, but karma-yoga is action performed by the devotee for the satisfaction of the Lord. Karma-yoga is based on bhakti, or pleasing the Lord, whereas karma is based on pleasing the senses of the performer himself.
(Srimad Bhagavatam---3:1:4---purport).

Liberation from material bondage is, therefore, a by-product of devotional service. Attainment of spiritual knowledge is not sufficient to insure liberation. Such knowledge must be overcoated with devotional service so that ultimately the devotional service alone predominates. Then liberation is made possible. Even the reactionary work of the fruitive workers can lead one to liberation when it is overcoated with devotional service. Karma overcoated with devotional service is called karma-yoga. Similarly, empirical knowledge overcoated with devotional service is called jñāna-yoga. But pure bhakti-yoga is independent of such karma and jñāna because it alone can not only endow one with liberation from conditional life but also award one the transcendental loving service of the Lord.
(Srimad Bhagavatam---1:2:15---purport).

In Bhagavad-gītā there are descriptions of karma-yoga, jñāna-yoga, bhakti-yoga, dhyāna-yoga, etc., but unless one comes to the point of bhakti-yoga, these other yogas cannot help one attain the highest perfection of life.
(Srimad Bhagavatam---4:24:53---purport).

If Hari, the Supreme Personality of Godhead, is not worshiped, there is no point in practicing meditational yoga, performing karma-yoga or culturing empiric knowledge.
(Srimad Bhagavatam---4:23:8---purport).

In other practices—like karma-yoga, jñāna-yoga and dhyāna-yoga—one may not be confident about his progress, but in bhakti-yoga one can become directly aware of his progress in spiritual life, just as a person who eats can understand that his hunger is satisfied.
(Srimad Bhagavatam---4:21:32---purport).

In the Bhagavad-gītā, three principal subjects have been explained by Lord Śrī Kṛṣṇa, namely karma-yoga, jñāna-yoga and bhakti-yoga, butone can reach the Vaikuṇṭha planets by the practice of bhakti-yoga only.
(Srimad Bhagavatam---2:2:17---purport).